20290816820 has 24 divisors (see below), whose sum is σ = 45117228744. Its totient is φ = 7638895616.

The previous prime is 20290816817. The next prime is 20290816841. The reversal of 20290816820 is 2861809202.

It can be written as a sum of positive squares in 4 ways, for example, as 3686432656 + 16604384164 = 60716^2 + 128858^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29839097 + ... + 29839776.

It is an arithmetic number, because the mean of its divisors is an integer number (1879884531).

Almost surely, 2^20290816820 is an apocalyptic number.

20290816820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20290816820 is an abundant number, since it is smaller than the sum of its proper divisors (24826411924).

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

20290816820 is a wasteful number, since it uses less digits than its factorization.

20290816820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59678899 (or 59678897 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 38.

The spelling of 20290816820 in words is "twenty billion, two hundred ninety million, eight hundred sixteen thousand, eight hundred twenty".