20508790 has 16 divisors (see below), whose sum is σ = 38859120. Its totient is φ = 7771680.

The previous prime is 20508781. The next prime is 20508791. The reversal of 20508790 is 9780502.

It is a super-2 number, since 2×20508790² = 841220934528200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20508791) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 53781 + ... + 54160.

It is an arithmetic number, because the mean of its divisors is an integer number (2428695).

Almost surely, 2^20508790 is an apocalyptic number.

20508790 is a deficient number, since it is larger than the sum of its proper divisors (18350330).

20508790 is a wasteful number, since it uses less digits than its factorization.

20508790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107967.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 20508790 is about 4528.6631581516. The cubic root of 20508790 is about 273.7242951059.

The spelling of 20508790 in words is "twenty million, five hundred eight thousand, seven hundred ninety".