21615544602104 has 64 divisors (see below), whose sum is σ = 44662149100800. Its totient is φ = 9761868762624.

The previous prime is 21615544602083. The next prime is 21615544602107. The reversal of 21615544602104 is 40120644551612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21615544602107) 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, 8996657 + ... + 11143200.

It is an arithmetic number, because the mean of its divisors is an integer number (697846079700).

Almost surely, 2^{21615544602104} is an apocalyptic number.

It is an amenable number.

21615544602104 is an abundant number, since it is smaller than the sum of its proper divisors (23046604498696).

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

21615544602104 is a wasteful number, since it uses less digits than its factorization.

21615544602104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20140212 (or 20140208 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 41.

The spelling of 21615544602104 in words is "twenty-one trillion, six hundred fifteen billion, five hundred forty-four million, six hundred two thousand, one hundred four".