921665281156 has 9 divisors (see below), whose sum is σ = 1612917602149. Its totient is φ = 460831680544.

The previous prime is 921665281127. The next prime is 921665281157. The reversal of 921665281156 is 651182566129.

The square root of 921665281156 is 960034.

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., 35777722500 + 885887558656 = 189150^2 + 941216^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921665281157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1680060 + ... + 2160076.

Almost surely, 2^921665281156 is an apocalyptic number.

921665281156 is the 960034-th square number.

It is an amenable number.

921665281156 is a deficient number, since it is larger than the sum of its proper divisors (691252320993).

921665281156 is an frugal number, since it uses more digits than its factorization.

921665281156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960038 (or 480019 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 52.

The spelling of 921665281156 in words is "nine hundred twenty-one billion, six hundred sixty-five million, two hundred eighty-one thousand, one hundred fifty-six".