21795782500 has 30 divisors (see below), whose sum is σ = 47663022638. Its totient is φ = 8718312000.

The previous prime is 21795782483. The next prime is 21795782513. The reversal of 21795782500 is 528759712.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 15383937024 + 6411845476 = 124032^2 + 80074^2 .

It is a super-2 number, since 2×21795782500² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4356657 + ... + 4361656.

Almost surely, 2^21795782500 is an apocalyptic number.

21795782500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21795782500 is an abundant number, since it is smaller than the sum of its proper divisors (25867240138).

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

21795782500 is an equidigital number, since it uses as much as digits as its factorization.

21795782500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8718337 (or 8718320 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 46.

The spelling of 21795782500 in words is "twenty-one billion, seven hundred ninety-five million, seven hundred eighty-two thousand, five hundred".