78640651 has 8 divisors (see below), whose sum is σ = 82092464. Its totient is φ = 75258720.

The previous prime is 78640633. The next prime is 78640673. The reversal of 78640651 is 15604687.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78640651 - 2⁵ = 78640619 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78640651.

It is not an unprimeable number, because it can be changed into a prime (78640631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15165 + ... + 19678.

It is an arithmetic number, because the mean of its divisors is an integer number (10261558).

Almost surely, 2^78640651 is an apocalyptic number.

78640651 is a deficient number, since it is larger than the sum of its proper divisors (3451813).

78640651 is a wasteful number, since it uses less digits than its factorization.

78640651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34941.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 78640651 is about 8867.9564162213. The cubic root of 78640651 is about 428.4324591381.

The spelling of 78640651 in words is "seventy-eight million, six hundred forty thousand, six hundred fifty-one".