78406408 has 8 divisors (see below), whose sum is σ = 147012030. Its totient is φ = 39203200.

The previous prime is 78406403. The next prime is 78406417. The reversal of 78406408 is 80460487.

It can be written as a sum of positive squares in only one way, i.e., 73307844 + 5098564 = 8562^2 + 2258^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×78406408² = 12295129630924928, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78406403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4900393 + ... + 4900408.

Almost surely, 2^78406408 is an apocalyptic number.

It is an amenable number.

78406408 is a deficient number, since it is larger than the sum of its proper divisors (68605622).

78406408 is a wasteful number, since it uses less digits than its factorization.

78406408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9800807 (or 9800803 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 37.

The square root of 78406408 is about 8854.7392959929. The cubic root of 78406408 is about 428.0066525882.

The spelling of 78406408 in words is "seventy-eight million, four hundred six thousand, four hundred eight".