78926409 has 12 divisors (see below), whose sum is σ = 118961856. Its totient is φ = 50329752.

The previous prime is 78926401. The next prime is 78926413. The reversal of 78926409 is 90462987.

It is a happy number.

It is not a de Polignac number, because 78926409 - 2³ = 78926401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78926401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190437 + ... + 190850.

It is an arithmetic number, because the mean of its divisors is an integer number (9913488).

Almost surely, 2^78926409 is an apocalyptic number.

It is an amenable number.

78926409 is a deficient number, since it is larger than the sum of its proper divisors (40035447).

78926409 is a wasteful number, since it uses less digits than its factorization.

78926409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381316 (or 381313 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 78926409 is about 8884.0536355878. The cubic root of 78926409 is about 428.9507661888.

The spelling of 78926409 in words is "seventy-eight million, nine hundred twenty-six thousand, four hundred nine".