20902090 has 64 divisors (see below), whose sum is σ = 44115840. Its totient is φ = 7050240.

The previous prime is 20902081. The next prime is 20902103. The reversal of 20902090 is 9020902.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 152502 + ... + 152638.

It is an arithmetic number, because the mean of its divisors is an integer number (689310).

Almost surely, 2^20902090 is an apocalyptic number.

20902090 is an abundant number, since it is smaller than the sum of its proper divisors (23213750).

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

20902090 is a wasteful number, since it uses less digits than its factorization.

20902090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 20902090 is about 4571.8803571397. The cubic root of 20902090 is about 275.4629776898.

Adding to 20902090 its reverse (9020902), we get a palindrome (29922992).

The spelling of 20902090 in words is "twenty million, nine hundred two thousand, ninety".