21376564100 has 72 divisors (see below), whose sum is σ = 48126477000. Its totient is φ = 8231731200.

The previous prime is 21376564039. The next prime is 21376564127. The reversal of 21376564100 is 146567312.

It can be written as a sum of positive squares in 12 ways, for example, as 1628445316 + 19748118784 = 40354^2 + 140528^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1001540 + ... + 1022660.

Almost surely, 2^21376564100 is an apocalyptic number.

21376564100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21376564100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24063238500).

21376564100 is an abundant number, since it is smaller than the sum of its proper divisors (26749912900).

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

21376564100 is a wasteful number, since it uses less digits than its factorization.

21376564100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21513 (or 21506 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 35.

The spelling of 21376564100 in words is "twenty-one billion, three hundred seventy-six million, five hundred sixty-four thousand, one hundred".