77631645 has 32 divisors (see below), whose sum is σ = 152877312. Its totient is φ = 32758272.

The previous prime is 77631629. The next prime is 77631649. The reversal of 77631645 is 54613677.

It is not a de Polignac number, because 77631645 - 2⁴ = 77631629 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77631649) 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, 27072 + ... + 29801.

It is an arithmetic number, because the mean of its divisors is an integer number (4777416).

Almost surely, 2^77631645 is an apocalyptic number.

It is an amenable number.

77631645 is a deficient number, since it is larger than the sum of its proper divisors (75245667).

77631645 is a wasteful number, since it uses less digits than its factorization.

77631645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56901.

The product of its digits is 105840, while the sum is 39.

The square root of 77631645 is about 8810.8821919261. The cubic root of 77631645 is about 426.5922189306.

The spelling of 77631645 in words is "seventy-seven million, six hundred thirty-one thousand, six hundred forty-five".