77557961 has 8 divisors (see below), whose sum is σ = 88437384. Its totient is φ = 67380480.

The previous prime is 77557951. The next prime is 77557993. The reversal of 77557961 is 16975577.

It can be written as a sum of positive squares in 4 ways, for example, as 732736 + 76825225 = 856^2 + 8765^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77557961 - 2¹⁰ = 77556937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77557951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175250 + ... + 175691.

It is an arithmetic number, because the mean of its divisors is an integer number (11054673).

Almost surely, 2^77557961 is an apocalyptic number.

It is an amenable number.

77557961 is a deficient number, since it is larger than the sum of its proper divisors (10879423).

77557961 is a wasteful number, since it uses less digits than its factorization.

77557961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350971.

The product of its digits is 463050, while the sum is 47.

The square root of 77557961 is about 8806.6997791454. The cubic root of 77557961 is about 426.4572096777.

The spelling of 77557961 in words is "seventy-seven million, five hundred fifty-seven thousand, nine hundred sixty-one".