997421631 has 8 divisors (see below), whose sum is σ = 1336579200. Its totient is φ = 661605912.

The previous prime is 997421627. The next prime is 997421641. The reversal of 997421631 is 136124799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 997421631 - 2² = 997421627 is a prime.

It is a super-2 number, since 2×997421631² = 1989699819973400322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997421641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 834765 + ... + 835958.

It is an arithmetic number, because the mean of its divisors is an integer number (167072400).

Almost surely, 2^997421631 is an apocalyptic number.

997421631 is a deficient number, since it is larger than the sum of its proper divisors (339157569).

997421631 is a wasteful number, since it uses less digits than its factorization.

997421631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1670925.

The product of its digits is 81648, while the sum is 42.

The square root of 997421631 is about 31581.9826958347. The cubic root of 997421631 is about 999.1398039416.

The spelling of 997421631 in words is "nine hundred ninety-seven million, four hundred twenty-one thousand, six hundred thirty-one".