921156533361 has 135 divisors (see below), whose sum is σ = 1504696211863. Its totient is φ = 563883482880.

The previous prime is 921156533321. The next prime is 921156533383. The reversal of 921156533361 is 163335651129.

The square root of 921156533361 is 959769.

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

921156533361 is a `hidden beast` number, since 9 + 2 + 1 + 1 + 56 + 533 + 3 + 61 = 666.

It can be written as a sum of positive squares in 7 ways, for example, as 435904973361 + 485251560000 = 660231^2 + 696600^2 .

It is not a de Polignac number, because 921156533361 - 2¹¹ = 921156531313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921156533321) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 22467232501 + ... + 22467232541.

Almost surely, 2^921156533361 is an apocalyptic number.

921156533361 is the 959769-th square number.

921156533361 is the 479885-th centered octagonal number.

It is an amenable number.

921156533361 is a deficient number, since it is larger than the sum of its proper divisors (583539678502).

921156533361 is an frugal number, since it uses more digits than its factorization.

921156533361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 61 counting only the distinct ones).

The product of its digits is 437400, while the sum is 45.

It can be divided in two parts, 92115 and 6533361, that added together give a square (6625476 = 2574²).

The spelling of 921156533361 in words is "nine hundred twenty-one billion, one hundred fifty-six million, five hundred thirty-three thousand, three hundred sixty-one".