78402590 has 32 divisors (see below), whose sum is σ = 161590464. Its totient is φ = 26830080.

The previous prime is 78402559. The next prime is 78402601. The reversal of 78402590 is 9520487.

It is a happy number.

It is a super-2 number, since 2×78402590² = 12293932237416200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 78402590.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70922 + ... + 72018.

It is an arithmetic number, because the mean of its divisors is an integer number (5049702).

Almost surely, 2^78402590 is an apocalyptic number.

78402590 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

78402590 is an abundant number, since it is smaller than the sum of its proper divisors (83187874).

78402590 is a wasteful number, since it uses less digits than its factorization.

78402590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 78402590 is about 8854.5237026054. The cubic root of 78402590 is about 427.9997052142. Note that the first 3 decimals are identical.

The spelling of 78402590 in words is "seventy-eight million, four hundred two thousand, five hundred ninety".