20031156 has 36 divisors (see below), whose sum is σ = 50791104. Its totient is φ = 6656400.

The previous prime is 20031139. The next prime is 20031169. The reversal of 20031156 is 65113002.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14871 + ... + 16161.

It is an arithmetic number, because the mean of its divisors is an integer number (1410864).

Almost surely, 2^20031156 is an apocalyptic number.

It is an amenable number.

20031156 is an abundant number, since it is smaller than the sum of its proper divisors (30759948).

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

20031156 is a wasteful number, since it uses less digits than its factorization.

20031156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732 (or 1727 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 20031156 is about 4475.6179461612. The cubic root of 20031156 is about 271.5826391906.

Adding to 20031156 its reverse (65113002), we get a palindrome (85144158).

The spelling of 20031156 in words is "twenty million, thirty-one thousand, one hundred fifty-six".