81979710 has 32 divisors (see below), whose sum is σ = 197627040. Its totient is φ = 21763968.

The previous prime is 81979691. The next prime is 81979721. The reversal of 81979710 is 1797918.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 904 + ... + 12836.

It is an arithmetic number, because the mean of its divisors is an integer number (6175845).

Almost surely, 2^81979710 is an apocalyptic number.

81979710 is an abundant number, since it is smaller than the sum of its proper divisors (115647330).

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

81979710 is a wasteful number, since it uses less digits than its factorization.

81979710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12172.

The product of its (nonzero) digits is 31752, while the sum is 42.

The square root of 81979710 is about 9054.2647409936. The cubic root of 81979710 is about 434.4123124789.

The spelling of 81979710 in words is "eighty-one million, nine hundred seventy-nine thousand, seven hundred ten".