164747756421 has 6 divisors (see below), whose sum is σ = 237968981510. Its totient is φ = 109831837608.

The previous prime is 164747756417. The next prime is 164747756441. The reversal of 164747756421 is 124657747461.

164747756421 is a `hidden beast` number, since 1 + 6 + 4 + 7 + 4 + 77 + 564 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 163449595521 + 1298160900 = 404289^2 + 36030^2 .

It is not a de Polignac number, because 164747756421 - 2² = 164747756417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164747756441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9152653126 + ... + 9152653143.

Almost surely, 2^164747756421 is an apocalyptic number.

It is an amenable number.

164747756421 is a deficient number, since it is larger than the sum of its proper divisors (73221225089).

164747756421 is a wasteful number, since it uses less digits than its factorization.

164747756421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18305306275 (or 18305306272 counting only the distinct ones).

The product of its digits is 7902720, while the sum is 54.

The spelling of 164747756421 in words is "one hundred sixty-four billion, seven hundred forty-seven million, seven hundred fifty-six thousand, four hundred twenty-one".