78947391 has 16 divisors (see below), whose sum is σ = 106573824. Its totient is φ = 51980544.

The previous prime is 78947389. The next prime is 78947411. The reversal of 78947391 is 19374987.

It is not a de Polignac number, because 78947391 - 2¹ = 78947389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78947391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78947311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134200 + ... + 134786.

It is an arithmetic number, because the mean of its divisors is an integer number (6660864).

Almost surely, 2^78947391 is an apocalyptic number.

78947391 is a deficient number, since it is larger than the sum of its proper divisors (27626433).

78947391 is a wasteful number, since it uses less digits than its factorization.

78947391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070.

The product of its digits is 381024, while the sum is 48.

The square root of 78947391 is about 8885.2344369746. The cubic root of 78947391 is about 428.9887739468.

The spelling of 78947391 in words is "seventy-eight million, nine hundred forty-seven thousand, three hundred ninety-one".