9497731621921 has 9 divisors (see below), whose sum is σ = 9928704697779. Its totient is φ = 9084718968336.

The previous prime is 9497731621913. The next prime is 9497731621957. The reversal of 9497731621921 is 1291261377949.

The square root of 9497731621921 is 3081839.

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., 4076583093025 + 5421148528896 = 2019055^2 + 2328336^2 .

It is not a de Polignac number, because 9497731621921 - 2³ = 9497731621913 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 9497731621921.

It is not an unprimeable number, because it can be changed into a prime (9497731621321) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 70815301 + ... + 70949293.

Almost surely, 2^{9497731621921} is an apocalyptic number.

9497731621921 is the 3081839-th square number.

9497731621921 is the 1540920-th centered octagonal number.

It is an amenable number.

9497731621921 is a deficient number, since it is larger than the sum of its proper divisors (430973075858).

9497731621921 is an frugal number, since it uses more digits than its factorization.

9497731621921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268032 (or 134016 counting only the distinct ones).

The product of its digits is 10287648, while the sum is 61.

The spelling of 9497731621921 in words is "nine trillion, four hundred ninety-seven billion, seven hundred thirty-one million, six hundred twenty-one thousand, nine hundred twenty-one".