78213904 has 20 divisors (see below), whose sum is σ = 155064976. Its totient is φ = 38197152.

The previous prime is 78213887. The next prime is 78213907. The reversal of 78213904 is 40931287.

It is a super-2 number, since 2×78213904² = 12234829557842432, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78213904.

It is not an unprimeable number, because it can be changed into a prime (78213907) 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 3 ways as a sum of consecutive naturals, for example, 56154 + ... + 57529.

Almost surely, 2^78213904 is an apocalyptic number.

It is an amenable number.

78213904 is a deficient number, since it is larger than the sum of its proper divisors (76851072).

78213904 is a wasteful number, since it uses less digits than its factorization.

78213904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113734 (or 113728 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 78213904 is about 8843.8625045847. The cubic root of 78213904 is about 427.6560838124.

The spelling of 78213904 in words is "seventy-eight million, two hundred thirteen thousand, nine hundred four".