77661251 has 2 divisors, whose sum is σ = 77661252. Its totient is φ = 77661250.

The previous prime is 77661239. The next prime is 77661277. The reversal of 77661251 is 15216677.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77661251 - 2¹⁰ = 77660227 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77631251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38830625 + 38830626.

It is an arithmetic number, because the mean of its divisors is an integer number (38830626).

Almost surely, 2^77661251 is an apocalyptic number.

77661251 is a deficient number, since it is larger than the sum of its proper divisors (1).

77661251 is an equidigital number, since it uses as much as digits as its factorization.

77661251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 35.

The square root of 77661251 is about 8812.5621132563. The cubic root of 77661251 is about 426.6464411664.

The spelling of 77661251 in words is "seventy-seven million, six hundred sixty-one thousand, two hundred fifty-one".