21100154664 has 32 divisors (see below), whose sum is σ = 55526724000. Its totient is φ = 6663206592.

The previous prime is 21100154659. The next prime is 21100154771. The reversal of 21100154664 is 46645100112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23135679 + ... + 23136590.

It is an arithmetic number, because the mean of its divisors is an integer number (1735210125).

Almost surely, 2^21100154664 is an apocalyptic number.

21100154664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21100154664 is an abundant number, since it is smaller than the sum of its proper divisors (34426569336).

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

21100154664 is a wasteful number, since it uses less digits than its factorization.

21100154664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46272297 (or 46272293 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

Adding to 21100154664 its reverse (46645100112), we get a palindrome (67745254776).

The spelling of 21100154664 in words is "twenty-one billion, one hundred million, one hundred fifty-four thousand, six hundred sixty-four".