78251388 has 12 divisors (see below), whose sum is σ = 182586600. Its totient is φ = 26083792.

The previous prime is 78251353. The next prime is 78251399. The reversal of 78251388 is 88315287.

It is a happy number.

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

It is a super-2 number, since 2×78251388² = 12246559447853088, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3260463 + ... + 3260486.

It is an arithmetic number, because the mean of its divisors is an integer number (15215550).

Almost surely, 2^78251388 is an apocalyptic number.

It is an amenable number.

78251388 is an abundant number, since it is smaller than the sum of its proper divisors (104335212).

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

78251388 is a wasteful number, since it uses less digits than its factorization.

78251388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6520956 (or 6520954 counting only the distinct ones).

The product of its digits is 107520, while the sum is 42.

The square root of 78251388 is about 8845.9814605277. The cubic root of 78251388 is about 427.7243909363.

The spelling of 78251388 in words is "seventy-eight million, two hundred fifty-one thousand, three hundred eighty-eight".