77997613 has 4 divisors (see below), whose sum is σ = 78025248. Its totient is φ = 77969980.

The previous prime is 77997583. The next prime is 77997631. The reversal of 77997613 is 31679977.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77997613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77997013) 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, 9031 + ... + 15412.

It is an arithmetic number, because the mean of its divisors is an integer number (19506312).

Almost surely, 2^77997613 is an apocalyptic number.

It is an amenable number.

77997613 is a deficient number, since it is larger than the sum of its proper divisors (27635).

77997613 is a wasteful number, since it uses less digits than its factorization.

77997613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27634.

The product of its digits is 500094, while the sum is 49.

The square root of 77997613 is about 8831.6257280299. The cubic root of 77997613 is about 427.2615096483.

The spelling of 77997613 in words is "seventy-seven million, nine hundred ninety-seven thousand, six hundred thirteen".