78987929 has 4 divisors (see below), whose sum is σ = 79008384. Its totient is φ = 78967476.

The previous prime is 78987901. The next prime is 78987941. The reversal of 78987929 is 92978987.

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.

It is a cyclic number.

It is not a de Polignac number, because 78987929 - 2⁸ = 78987673 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 (78987989) 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, 2477 + ... + 12810.

It is an arithmetic number, because the mean of its divisors is an integer number (19752096).

Almost surely, 2^78987929 is an apocalyptic number.

It is an amenable number.

78987929 is a deficient number, since it is larger than the sum of its proper divisors (20455).

78987929 is a wasteful number, since it uses less digits than its factorization.

78987929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20454.

The product of its digits is 4572288, while the sum is 59.

The square root of 78987929 is about 8887.5153445718. The cubic root of 78987929 is about 429.0621872710.

The spelling of 78987929 in words is "seventy-eight million, nine hundred eighty-seven thousand, nine hundred twenty-nine".