78388390 has 8 divisors (see below), whose sum is σ = 141099120. Its totient is φ = 31355352.

The previous prime is 78388381. The next prime is 78388397. The reversal of 78388390 is 9388387.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×78388390² = 12289479373584200, 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 78388390.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78388397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3919410 + ... + 3919429.

It is an arithmetic number, because the mean of its divisors is an integer number (17637390).

Almost surely, 2^78388390 is an apocalyptic number.

78388390 is a deficient number, since it is larger than the sum of its proper divisors (62710730).

78388390 is a wasteful number, since it uses less digits than its factorization.

78388390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7838846.

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 78388390 is about 8853.7218162759. The cubic root of 78388390 is about 427.9738643895.

The spelling of 78388390 in words is "seventy-eight million, three hundred eighty-eight thousand, three hundred ninety".