78421264 has 10 divisors (see below), whose sum is σ = 151941230. Its totient is φ = 39210624.

The previous prime is 78421247. The next prime is 78421271. The reversal of 78421264 is 46212487.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 73616400 + 4804864 = 8580^2 + 2192^2 .

It is a super-2 number, since 2×78421264² = 12299789294715392, which contains 22 as substring.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2450649 + ... + 2450680.

It is an arithmetic number, because the mean of its divisors is an integer number (15194123).

Almost surely, 2^78421264 is an apocalyptic number.

It is an amenable number.

78421264 is a deficient number, since it is larger than the sum of its proper divisors (73519966).

78421264 is a wasteful number, since it uses less digits than its factorization.

78421264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4901337 (or 4901331 counting only the distinct ones).

The product of its digits is 21504, while the sum is 34.

The square root of 78421264 is about 8855.5781290664. The cubic root of 78421264 is about 428.0336829694.

The spelling of 78421264 in words is "seventy-eight million, four hundred twenty-one thousand, two hundred sixty-four".