79881820 has 24 divisors (see below), whose sum is σ = 168001344. Its totient is φ = 31905216.

The previous prime is 79881799. The next prime is 79881821. The reversal of 79881820 is 2818897.

It is a super-2 number, since 2×79881820² = 12762210333024800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79881821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12877 + ... + 18043.

It is an arithmetic number, because the mean of its divisors is an integer number (7000056).

Almost surely, 2^79881820 is an apocalyptic number.

It is an amenable number.

79881820 is an abundant number, since it is smaller than the sum of its proper divisors (88119524).

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

79881820 is a wasteful number, since it uses less digits than its factorization.

79881820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5949 (or 5947 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 79881820 is about 8937.6630055065. The cubic root of 79881820 is about 430.6746575319.

The spelling of 79881820 in words is "seventy-nine million, eight hundred eighty-one thousand, eight hundred twenty".