131511640 has 64 divisors (see below), whose sum is σ = 325503360. Its totient is φ = 47516160.

The previous prime is 131511629. The next prime is 131511671. The reversal of 131511640 is 46115131.

It is a super-2 number, since 2×131511640² = 34590622910979200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21750 + ... + 27130.

It is an arithmetic number, because the mean of its divisors is an integer number (5085990).

Almost surely, 2^131511640 is an apocalyptic number.

131511640 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 131511640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162751680).

131511640 is an abundant number, since it is smaller than the sum of its proper divisors (193991720).

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

131511640 is a wasteful number, since it uses less digits than its factorization.

131511640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5452 (or 5448 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 131511640 is about 11467.8524580673. The cubic root of 131511640 is about 508.5356430835.

Adding to 131511640 its reverse (46115131), we get a palindrome (177626771).

The spelling of 131511640 in words is "one hundred thirty-one million, five hundred eleven thousand, six hundred forty".