21100869504 has 576 divisors, whose sum is σ = 73379779200. Its totient is φ = 5767557120.

The previous prime is 21100869487. The next prime is 21100869521. The reversal of 21100869504 is 40596800112.

It is an interprime number because it is at equal distance from previous prime (21100869487) and next prime (21100869521).

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 126352429 + ... + 126352595.

It is an arithmetic number, because the mean of its divisors is an integer number (127395450).

Almost surely, 2^21100869504 is an apocalyptic number.

21100869504 is a gapful number since it is divisible by the number (24) 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 21100869504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36689889600).

21100869504 is an abundant number, since it is smaller than the sum of its proper divisors (52278909696).

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

21100869504 is a wasteful number, since it uses less digits than its factorization.

21100869504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 255 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 21100869504 in words is "twenty-one billion, one hundred million, eight hundred sixty-nine thousand, five hundred four".