67920561 has 6 divisors (see below), whose sum is σ = 98107490. Its totient is φ = 45280368.

The previous prime is 67920557. The next prime is 67920563. The reversal of 67920561 is 16502976.

67920561 is a `hidden beast` number, since 6 + 7 + 92 + 0 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 66830625 + 1089936 = 8175^2 + 1044^2 .

It is not a de Polignac number, because 67920561 - 2² = 67920557 is a prime.

It is a super-2 number, since 2×67920561² = 9226405213109442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67920563) 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, 3773356 + ... + 3773373.

Almost surely, 2^67920561 is an apocalyptic number.

It is an amenable number.

67920561 is a deficient number, since it is larger than the sum of its proper divisors (30186929).

67920561 is a wasteful number, since it uses less digits than its factorization.

67920561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7546735 (or 7546732 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 67920561 is about 8241.3931467926. The cubic root of 67920561 is about 408.0065058074.

The spelling of 67920561 in words is "sixty-seven million, nine hundred twenty thousand, five hundred sixty-one".