76561257 has 4 divisors (see below), whose sum is σ = 102081680. Its totient is φ = 51040836.

The previous prime is 76561249. The next prime is 76561297. The reversal of 76561257 is 75216567.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75216567 = 3 ⋅25072189.

It is not a de Polignac number, because 76561257 - 2³ = 76561249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76561297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12760207 + ... + 12760212.

It is an arithmetic number, because the mean of its divisors is an integer number (25520420).

Almost surely, 2^76561257 is an apocalyptic number.

It is an amenable number.

76561257 is a deficient number, since it is larger than the sum of its proper divisors (25520423).

76561257 is a wasteful number, since it uses less digits than its factorization.

76561257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25520422.

The product of its digits is 88200, while the sum is 39.

The square root of 76561257 is about 8749.9289711403. The cubic root of 76561257 is about 424.6225151056.

The spelling of 76561257 in words is "seventy-six million, five hundred sixty-one thousand, two hundred fifty-seven".