81979602 has 8 divisors (see below), whose sum is σ = 163959216. Its totient is φ = 27326532.

The previous prime is 81979589. The next prime is 81979603. The reversal of 81979602 is 20697918.

It is a sphenic number, since it is the product of 3 distinct primes.

81979602 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81979603) 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 3 ways as a sum of consecutive naturals, for example, 6831628 + ... + 6831639.

It is an arithmetic number, because the mean of its divisors is an integer number (20494902).

Almost surely, 2^81979602 is an apocalyptic number.

81979602 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81979602 is a wasteful number, since it uses less digits than its factorization.

81979602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13663272.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 81979602 is about 9054.2587769513. The cubic root of 81979602 is about 434.4121217141.

The spelling of 81979602 in words is "eighty-one million, nine hundred seventy-nine thousand, six hundred two".