20156231 has 8 divisors (see below), whose sum is σ = 21369984. Its totient is φ = 18977760.

The previous prime is 20156219. The next prime is 20156243. The reversal of 20156231 is 13265102.

It is an interprime number because it is at equal distance from previous prime (20156219) and next prime (20156243).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20156231 is a prime.

It is a super-2 number, since 2×20156231² = 812547296250722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20156281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7640 + ... + 9933.

It is an arithmetic number, because the mean of its divisors is an integer number (2671248).

Almost surely, 2^20156231 is an apocalyptic number.

20156231 is a deficient number, since it is larger than the sum of its proper divisors (1213753).

20156231 is a wasteful number, since it uses less digits than its factorization.

20156231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17641.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20156231 is about 4489.5691330015. The cubic root of 20156231 is about 272.1467228514.

The spelling of 20156231 in words is "twenty million, one hundred fifty-six thousand, two hundred thirty-one".