78742644 has 12 divisors (see below), whose sum is σ = 183732864. Its totient is φ = 26247544.

The previous prime is 78742633. The next prime is 78742679. The reversal of 78742644 is 44624787.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×78742644² = 12400807968221472, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78742596 and 78742605.

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 3280932 + ... + 3280955.

It is an arithmetic number, because the mean of its divisors is an integer number (15311072).

Almost surely, 2^78742644 is an apocalyptic number.

It is an amenable number.

78742644 is an abundant number, since it is smaller than the sum of its proper divisors (104990220).

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

78742644 is a wasteful number, since it uses less digits than its factorization.

78742644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6561894 (or 6561892 counting only the distinct ones).

The product of its digits is 301056, while the sum is 42.

The square root of 78742644 is about 8873.7052013237. The cubic root of 78742644 is about 428.6175976293.

The spelling of 78742644 in words is "seventy-eight million, seven hundred forty-two thousand, six hundred forty-four".