81879772 has 12 divisors (see below), whose sum is σ = 154311976. Its totient is φ = 37790640.

The previous prime is 81879767. The next prime is 81879817. The reversal of 81879772 is 27797818.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 787254 + ... + 787357.

Almost surely, 2^81879772 is an apocalyptic number.

It is an amenable number.

81879772 is a deficient number, since it is larger than the sum of its proper divisors (72432204).

81879772 is a wasteful number, since it uses less digits than its factorization.

81879772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1574628 (or 1574626 counting only the distinct ones).

The product of its digits is 395136, while the sum is 49.

The square root of 81879772 is about 9048.7442222664. The cubic root of 81879772 is about 434.2357161351.

The spelling of 81879772 in words is "eighty-one million, eight hundred seventy-nine thousand, seven hundred seventy-two".