78397390 has 16 divisors (see below), whose sum is σ = 142133040. Its totient is φ = 31132800.

The previous prime is 78397379. The next prime is 78397399. The reversal of 78397390 is 9379387.

It is a super-2 number, since 2×78397390² = 12292301517624200, 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 78397390.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78397399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26811 + ... + 29590.

It is an arithmetic number, because the mean of its divisors is an integer number (8883315).

Almost surely, 2^78397390 is an apocalyptic number.

78397390 is a deficient number, since it is larger than the sum of its proper divisors (63735650).

78397390 is a wasteful number, since it uses less digits than its factorization.

78397390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56547.

The product of its (nonzero) digits is 285768, while the sum is 46.

The square root of 78397390 is about 8854.2300625181. The cubic root of 78397390 is about 427.9902427391.

It can be divided in two parts, 78397 and 390, that added together give a palindrome (78787).

The spelling of 78397390 in words is "seventy-eight million, three hundred ninety-seven thousand, three hundred ninety".