156121331 has 4 divisors (see below), whose sum is σ = 156202200. Its totient is φ = 156040464.

The previous prime is 156121327. The next prime is 156121333. The reversal of 156121331 is 133121651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133121651 = 13 ⋅10240127.

It is a cyclic number.

It is not a de Polignac number, because 156121331 - 2² = 156121327 is a prime.

It is a super-2 number, since 2×156121331² = 48747739986423122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 156121297 and 156121306.

It is not an unprimeable number, because it can be changed into a prime (156121333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37466 + ... + 41423.

It is an arithmetic number, because the mean of its divisors is an integer number (39050550).

Almost surely, 2^156121331 is an apocalyptic number.

156121331 is a deficient number, since it is larger than the sum of its proper divisors (80869).

156121331 is an equidigital number, since it uses as much as digits as its factorization.

156121331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80868.

The product of its digits is 540, while the sum is 23.

The square root of 156121331 is about 12494.8521799980. The cubic root of 156121331 is about 538.4607871298.

Adding to 156121331 its reverse (133121651), we get a palindrome (289242982).

The spelling of 156121331 in words is "one hundred fifty-six million, one hundred twenty-one thousand, three hundred thirty-one".