20890156 has 48 divisors (see below), whose sum is σ = 44255232. Its totient is φ = 8438400.

The previous prime is 20890099. The next prime is 20890183. The reversal of 20890156 is 65109802.

It is a Harshad number since it is a multiple of its sum of digits (31).

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, 35295 + ... + 35881.

It is an arithmetic number, because the mean of its divisors is an integer number (921984).

Almost surely, 2^20890156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20890156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22127616).

20890156 is an abundant number, since it is smaller than the sum of its proper divisors (23365076).

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

20890156 is a wasteful number, since it uses less digits than its factorization.

20890156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 20890156 is about 4570.5750185289. The cubic root of 20890156 is about 275.4105427258.

Adding to 20890156 its reverse (65109802), we get a palindrome (85999958).

The spelling of 20890156 in words is "twenty million, eight hundred ninety thousand, one hundred fifty-six".