64972161 has 6 divisors (see below), whose sum is σ = 93848690. Its totient is φ = 43314768.

The previous prime is 64972139. The next prime is 64972163. The reversal of 64972161 is 16127946.

64972161 is a `hidden beast` number, since 6 + 497 + 2 + 161 = 666.

It can be written as a sum of positive squares in only one way, i.e., 64400625 + 571536 = 8025^2 + 756^2 .

It is not a de Polignac number, because 64972161 - 2¹⁴ = 64955777 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 (64972163) 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, 3609556 + ... + 3609573.

Almost surely, 2^64972161 is an apocalyptic number.

It is an amenable number.

64972161 is a deficient number, since it is larger than the sum of its proper divisors (28876529).

64972161 is a wasteful number, since it uses less digits than its factorization.

64972161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7219135 (or 7219132 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 64972161 is about 8060.5310619090. The cubic root of 64972161 is about 402.0151661316.

The spelling of 64972161 in words is "sixty-four million, nine hundred seventy-two thousand, one hundred sixty-one".