31851383552209 has 81 divisors (see below), whose sum is σ = 37024520045427. Its totient is φ = 27384511145472.

The previous prime is 31851383552207. The next prime is 31851383552221. The reversal of 31851383552209 is 90225538315813.

The square root of 31851383552209 is 5643703.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 30010401330625 + 1840982221584 = 5478175^2 + 1356828^2 .

It is not a de Polignac number, because 31851383552209 - 2¹ = 31851383552207 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31851383552209.

It is not an unprimeable number, because it can be changed into a prime (31851383552207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 101761608637 + ... + 101761608949.

It is an arithmetic number, because the mean of its divisors is an integer number (457092840067).

Almost surely, 2^{31851383552209} is an apocalyptic number.

31851383552209 is the 5643703-rd square number.

31851383552209 is the 2821852-nd centered octagonal number.

It is an amenable number.

31851383552209 is a deficient number, since it is larger than the sum of its proper divisors (5173136493218).

31851383552209 is an frugal number, since it uses more digits than its factorization.

31851383552209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 55.

The spelling of 31851383552209 in words is "thirty-one trillion, eight hundred fifty-one billion, three hundred eighty-three million, five hundred fifty-two thousand, two hundred nine".