79840890 has 80 divisors (see below), whose sum is σ = 216101160. Its totient is φ = 21150720.

The previous prime is 79840879. The next prime is 79840909. The reversal of 79840890 is 9804897.

It can be written as a sum of positive squares in 4 ways, for example, as 79227801 + 613089 = 8901^2 + 783^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 195006 + ... + 195414.

Almost surely, 2^79840890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79840890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108050580).

79840890 is an abundant number, since it is smaller than the sum of its proper divisors (136260270).

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

79840890 is a wasteful number, since it uses less digits than its factorization.

79840890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 79840890 is about 8935.3729636764. The cubic root of 79840890 is about 430.6010883298.

The spelling of 79840890 in words is "seventy-nine million, eight hundred forty thousand, eight hundred ninety".