78921954 has 12 divisors (see below), whose sum is σ = 170997606. Its totient is φ = 26307312.

The previous prime is 78921949. The next prime is 78921959. The reversal of 78921954 is 45912987.

It is an interprime number because it is at equal distance from previous prime (78921949) and next prime (78921959).

It can be written as a sum of positive squares in only one way, i.e., 54686025 + 24235929 = 7395^2 + 4923^2 .

It is not an unprimeable number, because it can be changed into a prime (78921959) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2192259 + ... + 2192294.

Almost surely, 2^78921954 is an apocalyptic number.

78921954 is an abundant number, since it is smaller than the sum of its proper divisors (92075652).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78921954 is a wasteful number, since it uses less digits than its factorization.

78921954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4384561 (or 4384558 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 78921954 is about 8883.8029019109. The cubic root of 78921954 is about 428.9426953304.

The spelling of 78921954 in words is "seventy-eight million, nine hundred twenty-one thousand, nine hundred fifty-four".