77631965 has 4 divisors (see below), whose sum is σ = 93158364. Its totient is φ = 62105568.

The previous prime is 77631959. The next prime is 77631973. The reversal of 77631965 is 56913677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56913677 = 461 ⋅123457.

It can be written as a sum of positive squares in 2 ways, for example, as 40018276 + 37613689 = 6326^2 + 6133^2 .

It is a cyclic number.

It is not a de Polignac number, because 77631965 - 2⁴ = 77631949 is a prime.

It is a super-2 number, since 2×77631965² = 12053443979522450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7763192 + ... + 7763201.

It is an arithmetic number, because the mean of its divisors is an integer number (23289591).

Almost surely, 2^77631965 is an apocalyptic number.

It is an amenable number.

77631965 is a deficient number, since it is larger than the sum of its proper divisors (15526399).

77631965 is a wasteful number, since it uses less digits than its factorization.

77631965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15526398.

The product of its digits is 238140, while the sum is 44.

The square root of 77631965 is about 8810.9003512694. The cubic root of 77631965 is about 426.5928050719.

The spelling of 77631965 in words is "seventy-seven million, six hundred thirty-one thousand, nine hundred sixty-five".