82721740 has 24 divisors (see below), whose sum is σ = 173895120. Its totient is φ = 33054528.

The previous prime is 82721729. The next prime is 82721747. The reversal of 82721740 is 4712728.

It is not an unprimeable number, because it can be changed into a prime (82721747) 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, 28266 + ... + 31054.

It is an arithmetic number, because the mean of its divisors is an integer number (7245630).

Almost surely, 2^82721740 is an apocalyptic number.

It is an amenable number.

82721740 is an abundant number, since it is smaller than the sum of its proper divisors (91173380).

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

82721740 is a wasteful number, since it uses less digits than its factorization.

82721740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4281 (or 4279 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 82721740 is about 9095.1492566093. The cubic root of 82721740 is about 435.7190556036.

The spelling of 82721740 in words is "eighty-two million, seven hundred twenty-one thousand, seven hundred forty".