997165948921 has 4 divisors (see below), whose sum is σ = 997200293200. Its totient is φ = 997131604644.

The previous prime is 997165948879. The next prime is 997165948939. The reversal of 997165948921 is 129849561799.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 997165948921 - 2²³ = 997157560313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997145948921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17128551 + ... + 17186668.

It is an arithmetic number, because the mean of its divisors is an integer number (249300073300).

Almost surely, 2^997165948921 is an apocalyptic number.

It is an amenable number.

997165948921 is a deficient number, since it is larger than the sum of its proper divisors (34344279).

997165948921 is a wasteful number, since it uses less digits than its factorization.

997165948921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34344278.

The product of its digits is 88179840, while the sum is 70.

The spelling of 997165948921 in words is "nine hundred ninety-seven billion, one hundred sixty-five million, nine hundred forty-eight thousand, nine hundred twenty-one".