77525561 has 2 divisors, whose sum is σ = 77525562. Its totient is φ = 77525560.

The previous prime is 77525557. The next prime is 77525573. The reversal of 77525561 is 16552577.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52475536 + 25050025 = 7244^2 + 5005^2 .

It is a cyclic number.

It is not a de Polignac number, because 77525561 - 2² = 77525557 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77525521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38762780 + 38762781.

It is an arithmetic number, because the mean of its divisors is an integer number (38762781).

Almost surely, 2^77525561 is an apocalyptic number.

It is an amenable number.

77525561 is a deficient number, since it is larger than the sum of its proper divisors (1).

77525561 is an equidigital number, since it uses as much as digits as its factorization.

77525561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73500, while the sum is 38.

The square root of 77525561 is about 8804.8600783885. The cubic root of 77525561 is about 426.3978169435.

The spelling of 77525561 in words is "seventy-seven million, five hundred twenty-five thousand, five hundred sixty-one".