21167664427 has 64 divisors (see below), whose sum is σ = 28691712000. Its totient is φ = 15136450560.

The previous prime is 21167664391. The next prime is 21167664439. The reversal of 21167664427 is 72446676112.

It is not a de Polignac number, because 21167664427 - 2³¹ = 19020180779 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21167664467) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8926552 + ... + 8928922.

It is an arithmetic number, because the mean of its divisors is an integer number (448308000).

Almost surely, 2^21167664427 is an apocalyptic number.

21167664427 is a deficient number, since it is larger than the sum of its proper divisors (7524047573).

21167664427 is a wasteful number, since it uses less digits than its factorization.

21167664427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2636.

The product of its digits is 677376, while the sum is 46.

The spelling of 21167664427 in words is "twenty-one billion, one hundred sixty-seven million, six hundred sixty-four thousand, four hundred twenty-seven".