82971640 has 32 divisors (see below), whose sum is σ = 188167680. Its totient is φ = 32925312.

The previous prime is 82971619. The next prime is 82971643. The reversal of 82971640 is 4617928.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 82971640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82971643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3087 + ... + 13246.

It is an arithmetic number, because the mean of its divisors is an integer number (5880240).

Almost surely, 2^82971640 is an apocalyptic number.

It is an amenable number.

82971640 is an abundant number, since it is smaller than the sum of its proper divisors (105196040).

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

82971640 is a wasteful number, since it uses less digits than its factorization.

82971640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16471 (or 16467 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 82971640 is about 9108.8769889597. The cubic root of 82971640 is about 436.1573794279.

The spelling of 82971640 in words is "eighty-two million, nine hundred seventy-one thousand, six hundred forty".