78256394 has 4 divisors (see below), whose sum is σ = 117384594. Its totient is φ = 39128196.

The previous prime is 78256379. The next prime is 78256403. The reversal of 78256394 is 49365287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 77880625 + 375769 = 8825^2 + 613^2 .

It is a super-2 number, since 2×78256394² = 12248126403766472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19564097 + ... + 19564100.

Almost surely, 2^78256394 is an apocalyptic number.

78256394 is a deficient number, since it is larger than the sum of its proper divisors (39128200).

78256394 is a wasteful number, since it uses less digits than its factorization.

78256394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39128199.

The product of its digits is 362880, while the sum is 44.

The square root of 78256394 is about 8846.2644093425. The cubic root of 78256394 is about 427.7335117230.

The spelling of 78256394 in words is "seventy-eight million, two hundred fifty-six thousand, three hundred ninety-four".