20815477944 has 32 divisors (see below), whose sum is σ = 53307933840. Its totient is φ = 6769260800.

The previous prime is 20815477937. The next prime is 20815477967. The reversal of 20815477944 is 44977451802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10575987 + ... + 10577954.

Almost surely, 2^20815477944 is an apocalyptic number.

20815477944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20815477944 is an abundant number, since it is smaller than the sum of its proper divisors (32492455896).

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

20815477944 is a wasteful number, since it uses less digits than its factorization.

20815477944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21153991 (or 21153987 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 51.

The spelling of 20815477944 in words is "twenty billion, eight hundred fifteen million, four hundred seventy-seven thousand, nine hundred forty-four".