853611535921 has 9 divisors (see below), whose sum is σ = 884089162411. Its totient is φ = 824150785864.

The previous prime is 853611535901. The next prime is 853611535927. The reversal of 853611535921 is 129535116358.

The square root of 853611535921 is 923911.

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

It can be written as a sum of positive squares in only one way, i.e., 447613183521 + 405998352400 = 669039^2 + 637180^2 .

It is not a de Polignac number, because 853611535921 - 2⁷ = 853611535793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (853611535927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 26777490 + ... + 26809348.

Almost surely, 2^853611535921 is an apocalyptic number.

853611535921 is the 923911-st square number.

853611535921 is the 461956-th centered octagonal number.

It is an amenable number.

853611535921 is a deficient number, since it is larger than the sum of its proper divisors (30477626490).

853611535921 is an frugal number, since it uses more digits than its factorization.

853611535921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63776 (or 31888 counting only the distinct ones).

The product of its digits is 972000, while the sum is 49.

Multiplying 853611535921 by its sum of digits (49), we get a square (41826965260129 = 6467377²).

The spelling of 853611535921 in words is "eight hundred fifty-three billion, six hundred eleven million, five hundred thirty-five thousand, nine hundred twenty-one".