20819782400 has 54 divisors (see below), whose sum is σ = 51532230372. Its totient is φ = 8327910400.

The previous prime is 20819782393. The next prime is 20819782409. The reversal of 20819782400 is 428791802.

It is not an unprimeable number, because it can be changed into a prime (20819782409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1620146 + ... + 1632945.

Almost surely, 2^20819782400 is an apocalyptic number.

20819782400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20819782400 is an abundant number, since it is smaller than the sum of its proper divisors (30712447972).

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

20819782400 is an equidigital number, since it uses as much as digits as its factorization.

20819782400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3253117 (or 3253098 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 41.

The spelling of 20819782400 in words is "twenty billion, eight hundred nineteen million, seven hundred eighty-two thousand, four hundred".