851318083561 has 27 divisors (see below), whose sum is σ = 962144702967. Its totient is φ = 752676463440.

The previous prime is 851318083549. The next prime is 851318083571. The reversal of 851318083561 is 165380813158.

The square root of 851318083561 is 922669.

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

851318083561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 761771112025 + 89546971536 = 872795^2 + 299244^2 .

It is not a de Polignac number, because 851318083561 - 2⁵ = 851318083529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (851318083571) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 375525150 + ... + 375527416.

Almost surely, 2^851318083561 is an apocalyptic number.

851318083561 is the 922669-th square number.

851318083561 is the 461335-th centered octagonal number.

It is an amenable number.

851318083561 is a deficient number, since it is larger than the sum of its proper divisors (110826619406).

851318083561 is an frugal number, since it uses more digits than its factorization.

851318083561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4630 (or 2315 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 49.

Multiplying 851318083561 by its sum of digits (49), we get a square (41714586094489 = 6458683²).

The spelling of 851318083561 in words is "eight hundred fifty-one billion, three hundred eighteen million, eighty-three thousand, five hundred sixty-one".