78712961 has 4 divisors (see below), whose sum is σ = 78869952. Its totient is φ = 78555972.

The previous prime is 78712957. The next prime is 78712973. The reversal of 78712961 is 16921787.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16921787 = 53 ⋅319279.

It is a cyclic number.

It is not a de Polignac number, because 78712961 - 2² = 78712957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78712901) 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, 77741 + ... + 78746.

It is an arithmetic number, because the mean of its divisors is an integer number (19717488).

Almost surely, 2^78712961 is an apocalyptic number.

It is an amenable number.

78712961 is a deficient number, since it is larger than the sum of its proper divisors (156991).

78712961 is a wasteful number, since it uses less digits than its factorization.

78712961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156990.

The product of its digits is 42336, while the sum is 41.

The square root of 78712961 is about 8872.0325179747. The cubic root of 78712961 is about 428.5637333169.

The spelling of 78712961 in words is "seventy-eight million, seven hundred twelve thousand, nine hundred sixty-one".