997421637 has 32 divisors (see below), whose sum is σ = 1449463680. Its totient is φ = 607610880.

The previous prime is 997421627. The next prime is 997421641. The reversal of 997421637 is 736124799.

It is a happy number.

It is not a de Polignac number, because 997421637 - 2⁶ = 997421573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997421627) 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 31 ways as a sum of consecutive naturals, for example, 477798 + ... + 479880.

It is an arithmetic number, because the mean of its divisors is an integer number (45295740).

Almost surely, 2^997421637 is an apocalyptic number.

It is an amenable number.

997421637 is a deficient number, since it is larger than the sum of its proper divisors (452042043).

997421637 is a wasteful number, since it uses less digits than its factorization.

997421637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2373.

The product of its digits is 571536, while the sum is 48.

The square root of 997421637 is about 31581.9827908255. The cubic root of 997421637 is about 999.1398059450.

The spelling of 997421637 in words is "nine hundred ninety-seven million, four hundred twenty-one thousand, six hundred thirty-seven".