78921955 has 16 divisors (see below), whose sum is σ = 108380160. Its totient is φ = 54045792.

The previous prime is 78921949. The next prime is 78921959. The reversal of 78921955 is 55912987.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78921955 is a prime.

It is a super-3 number, since 3×78921955³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (78921959) 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 15 ways as a sum of consecutive naturals, for example, 49582 + ... + 51148.

It is an arithmetic number, because the mean of its divisors is an integer number (6773760).

Almost surely, 2^78921955 is an apocalyptic number.

78921955 is a deficient number, since it is larger than the sum of its proper divisors (29458205).

78921955 is a wasteful number, since it uses less digits than its factorization.

78921955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3018.

The product of its digits is 226800, while the sum is 46.

The square root of 78921955 is about 8883.8029581931. The cubic root of 78921955 is about 428.9426971421.

The spelling of 78921955 in words is "seventy-eight million, nine hundred twenty-one thousand, nine hundred fifty-five".