21661016555514 has 64 divisors (see below), whose sum is σ = 52443871200000. Its totient is φ = 5822525549568.

The previous prime is 21661016555501. The next prime is 21661016555543. The reversal of 21661016555514 is 41555561016612.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4130889 + ... + 7770860.

It is an arithmetic number, because the mean of its divisors is an integer number (819435487500).

Almost surely, 2^{21661016555514} is an apocalyptic number.

21661016555514 is an abundant number, since it is smaller than the sum of its proper divisors (30782854644486).

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

21661016555514 is a wasteful number, since it uses less digits than its factorization.

21661016555514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11904327.

The product of its (nonzero) digits is 1080000, while the sum is 48.

The spelling of 21661016555514 in words is "twenty-one trillion, six hundred sixty-one billion, sixteen million, five hundred fifty-five thousand, five hundred fourteen".