78090 has 32 divisors (see below), whose sum is σ = 198720. Its totient is φ = 19584.

The previous prime is 78079. The next prime is 78101. The reversal of 78090 is 9087.

78090 = T₈₁ + T₈₂ + ... + T₉₉.

It is an interprime number because it is at equal distance from previous prime (78079) and next prime (78101).

It is a nialpdrome in base 5.

It is a self number, because there is not a number n which added to its sum of digits gives 78090.

It is a congruent number.

It is an unprimeable number.

78090 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 502 + ... + 638.

It is an arithmetic number, because the mean of its divisors is an integer number (6210).

2⁷⁸⁰⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99360).

78090 is an abundant number, since it is smaller than the sum of its proper divisors (120630).

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

78090 is a wasteful number, since it uses less digits than its factorization.

78090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166.

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 78090 is about 279.4458802702. The cubic root of 78090 is about 42.7430138031.

The spelling of 78090 in words is "seventy-eight thousand, ninety".