131221335 has 16 divisors (see below), whose sum is σ = 239947776. Its totient is φ = 59986848.

The previous prime is 131221327. The next prime is 131221339. The reversal of 131221335 is 533122131.

It is not a de Polignac number, because 131221335 - 2³ = 131221327 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221339) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 624759 + ... + 624968.

It is an arithmetic number, because the mean of its divisors is an integer number (14996736).

Almost surely, 2^131221335 is an apocalyptic number.

131221335 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

131221335 is a deficient number, since it is larger than the sum of its proper divisors (108726441).

131221335 is a wasteful number, since it uses less digits than its factorization.

131221335 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249742.

The product of its digits is 540, while the sum is 21.

The square root of 131221335 is about 11455.1881259105. The cubic root of 131221335 is about 508.1611788863.

Adding to 131221335 its reverse (533122131), we get a palindrome (664343466).

The spelling of 131221335 in words is "one hundred thirty-one million, two hundred twenty-one thousand, three hundred thirty-five".