997121965 has 16 divisors (see below), whose sum is σ = 1386217728. Its totient is φ = 674372736.

The previous prime is 997121947. The next prime is 997121987. The reversal of 997121965 is 569121799.

It is a cyclic number.

It is not a de Polignac number, because 997121965 - 2⁷ = 997121837 is a prime.

It is a super-2 number, since 2×997121965² = 1988504426170922450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192577 + ... + 197686.

It is an arithmetic number, because the mean of its divisors is an integer number (86638608).

Almost surely, 2^997121965 is an apocalyptic number.

It is an amenable number.

997121965 is a deficient number, since it is larger than the sum of its proper divisors (389095763).

997121965 is a wasteful number, since it uses less digits than its factorization.

997121965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390348.

The product of its digits is 306180, while the sum is 49.

The square root of 997121965 is about 31577.2380837843. The cubic root of 997121965 is about 999.0397331828.

The spelling of 997121965 in words is "nine hundred ninety-seven million, one hundred twenty-one thousand, nine hundred sixty-five".