77715645 has 32 divisors (see below), whose sum is σ = 144242688. Its totient is φ = 34993728.

The previous prime is 77715641. The next prime is 77715661. The reversal of 77715645 is 54651777.

It is not a de Polignac number, because 77715645 - 2² = 77715641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77715597 and 77715606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77715641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1512 + ... + 12558.

It is an arithmetic number, because the mean of its divisors is an integer number (4507584).

Almost surely, 2^77715645 is an apocalyptic number.

It is an amenable number.

77715645 is a deficient number, since it is larger than the sum of its proper divisors (66527043).

77715645 is a wasteful number, since it uses less digits than its factorization.

77715645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11129.

The product of its digits is 205800, while the sum is 42.

The square root of 77715645 is about 8815.6477357027. The cubic root of 77715645 is about 426.7460257522.

The spelling of 77715645 in words is "seventy-seven million, seven hundred fifteen thousand, six hundred forty-five".