77331561 has 8 divisors (see below), whose sum is σ = 103213824. Its totient is φ = 51501840.

The previous prime is 77331533. The next prime is 77331571. The reversal of 77331561 is 16513377.

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

It is not a de Polignac number, because 77331561 - 2⁹ = 77331049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77331571) 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, 9561 + ... + 15686.

It is an arithmetic number, because the mean of its divisors is an integer number (12901728).

Almost surely, 2^77331561 is an apocalyptic number.

It is an amenable number.

77331561 is a deficient number, since it is larger than the sum of its proper divisors (25882263).

77331561 is a wasteful number, since it uses less digits than its factorization.

77331561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26271.

The product of its digits is 13230, while the sum is 33.

The square root of 77331561 is about 8793.8365347555. The cubic root of 77331561 is about 426.0418471532.

The spelling of 77331561 in words is "seventy-seven million, three hundred thirty-one thousand, five hundred sixty-one".