67661977 has 2 divisors, whose sum is σ = 67661978. Its totient is φ = 67661976.

The previous prime is 67661969. The next prime is 67661987. The reversal of 67661977 is 77916676.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61921161 + 5740816 = 7869^2 + 2396^2 .

It is a cyclic number.

It is not a de Polignac number, because 67661977 - 2³ = 67661969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67661977.

It is not a weakly prime, because it can be changed into another prime (67661927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33830988 + 33830989.

It is an arithmetic number, because the mean of its divisors is an integer number (33830989).

Almost surely, 2^67661977 is an apocalyptic number.

It is an amenable number.

67661977 is a deficient number, since it is larger than the sum of its proper divisors (1).

67661977 is an equidigital number, since it uses as much as digits as its factorization.

67661977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 666792, while the sum is 49.

The square root of 67661977 is about 8225.6900622379. The cubic root of 67661977 is about 407.4880661942.

The spelling of 67661977 in words is "sixty-seven million, six hundred sixty-one thousand, nine hundred seventy-seven".