21100004552 has 64 divisors (see below), whose sum is σ = 43671648960. Its totient is φ = 9477529600.

The previous prime is 21100004543. The next prime is 21100004557. The reversal of 21100004552 is 25540000112.

It is not an unprimeable number, because it can be changed into a prime (21100004557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3507227 + ... + 3513237.

It is an arithmetic number, because the mean of its divisors is an integer number (682369515).

Almost surely, 2^21100004552 is an apocalyptic number.

21100004552 is a gapful number since it is divisible by the number (22) 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 21100004552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21835824480).

21100004552 is an abundant number, since it is smaller than the sum of its proper divisors (22571644408).

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

21100004552 is a wasteful number, since it uses less digits than its factorization.

21100004552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6494 (or 6490 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

Adding to 21100004552 its reverse (25540000112), we get a palindrome (46640004664).

The spelling of 21100004552 in words is "twenty-one billion, one hundred million, four thousand, five hundred fifty-two".