81979702 has 16 divisors (see below), whose sum is σ = 140656032. Its totient is φ = 35104320.

The previous prime is 81979691. The next prime is 81979721. The reversal of 81979702 is 20797918.

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 7 ways as a sum of consecutive naturals, for example, 25252 + ... + 28312.

It is an arithmetic number, because the mean of its divisors is an integer number (8791002).

Almost surely, 2^81979702 is an apocalyptic number.

81979702 is a deficient number, since it is larger than the sum of its proper divisors (58676330).

81979702 is a wasteful number, since it uses less digits than its factorization.

81979702 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4983.

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 81979702 is about 9054.2642992128. The cubic root of 81979702 is about 434.4122983482.

The spelling of 81979702 in words is "eighty-one million, nine hundred seventy-nine thousand, seven hundred two".