82217920 has 28 divisors (see below), whose sum is σ = 195782184. Its totient is φ = 32887040.

The previous prime is 82217887. The next prime is 82217963. The reversal of 82217920 is 2971228.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128146 + ... + 128785.

Almost surely, 2^82217920 is an apocalyptic number.

82217920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

82217920 is an abundant number, since it is smaller than the sum of its proper divisors (113564264).

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

82217920 is a wasteful number, since it uses less digits than its factorization.

82217920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256948 (or 256938 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 82217920 is about 9067.4097734689. The cubic root of 82217920 is about 434.8326656338.

The spelling of 82217920 in words is "eighty-two million, two hundred seventeen thousand, nine hundred twenty".