78102090 has 64 divisors (see below), whose sum is σ = 227214720. Its totient is φ = 18933120.

The previous prime is 78102071. The next prime is 78102091. The reversal of 78102090 is 9020187.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78102091) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10179 + ... + 16118.

It is an arithmetic number, because the mean of its divisors is an integer number (3550230).

Almost surely, 2^78102090 is an apocalyptic number.

78102090 is an abundant number, since it is smaller than the sum of its proper divisors (149112630).

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

78102090 is a wasteful number, since it uses less digits than its factorization.

78102090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26324 (or 26318 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 78102090 is about 8837.5386844981. The cubic root of 78102090 is about 427.4521953316.

The spelling of 78102090 in words is "seventy-eight million, one hundred two thousand, ninety".