31728722380 has 24 divisors (see below), whose sum is σ = 66686785200. Its totient is φ = 12680733120.

The previous prime is 31728722321. The next prime is 31728722393. The reversal of 31728722380 is 8322782713.

It is a super-2 number, since 2×31728722380² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 648030 + ... + 695269.

It is an arithmetic number, because the mean of its divisors is an integer number (2778616050).

Almost surely, 2^31728722380 is an apocalyptic number.

It is an amenable number.

31728722380 is an abundant number, since it is smaller than the sum of its proper divisors (34958062820).

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

31728722380 is a wasteful number, since it uses less digits than its factorization.

31728722380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1344489 (or 1344487 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 43.

The spelling of 31728722380 in words is "thirty-one billion, seven hundred twenty-eight million, seven hundred twenty-two thousand, three hundred eighty".