20915090 has 32 divisors (see below), whose sum is σ = 44513280. Its totient is φ = 6922944.

The previous prime is 20915053. The next prime is 20915107. The reversal of 20915090 is 9051902.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3122 + ... + 7181.

It is an arithmetic number, because the mean of its divisors is an integer number (1391040).

Almost surely, 2^20915090 is an apocalyptic number.

20915090 is an abundant number, since it is smaller than the sum of its proper divisors (23598190).

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

20915090 is a wasteful number, since it uses less digits than its factorization.

20915090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10346.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 20915090 is about 4573.3018706401. The cubic root of 20915090 is about 275.5200736798.

Adding to 20915090 its reverse (9051902), we get a palindrome (29966992).

The spelling of 20915090 in words is "twenty million, nine hundred fifteen thousand, ninety".