81970588 has 54 divisors (see below), whose sum is σ = 172715816. Its totient is φ = 33343968.

The previous prime is 81970573. The next prime is 81970639. The reversal of 81970588 is 88507918.

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 17 ways as a sum of consecutive naturals, for example, 1389303 + ... + 1389361.

Almost surely, 2^81970588 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81970588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86357908).

81970588 is an abundant number, since it is smaller than the sum of its proper divisors (90745228).

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

81970588 is a wasteful number, since it uses less digits than its factorization.

81970588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 46.

The square root of 81970588 is about 9053.7609864630. The cubic root of 81970588 is about 434.3961993208.

The spelling of 81970588 in words is "eighty-one million, nine hundred seventy thousand, five hundred eighty-eight".