131235840 has 192 divisors, whose sum is σ = 460055700. Its totient is φ = 34603008.

The previous prime is 131235833. The next prime is 131235847. The reversal of 131235840 is 48532131.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (131235833) and next prime (131235847).

It can be written as a sum of positive squares in 2 ways, for example, as 124010496 + 7225344 = 11136^2 + 2688^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131235847) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1474516 + ... + 1474604.

Almost surely, 2^131235840 is an apocalyptic number.

131235840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131235840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230027850).

131235840 is an abundant number, since it is smaller than the sum of its proper divisors (328819860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131235840 is an frugal number, since it uses more digits than its factorization.

131235840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 131235840 is about 11455.8212276554. The cubic root of 131235840 is about 508.1799019757.

Adding to 131235840 its reverse (48532131), we get a palindrome (179767971).

The spelling of 131235840 in words is "one hundred thirty-one million, two hundred thirty-five thousand, eight hundred forty".