997437643525 has 12 divisors (see below), whose sum is σ = 1241635225572. Its totient is φ = 794845245440.

The previous prime is 997437643511. The next prime is 997437643549. The reversal of 997437643525 is 525346734799.

It is a Cunningham number, because it is equal to 998718²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 15463668609 + 981973974916 = 124353^2 + 990946^2 .

It is not a de Polignac number, because 997437643525 - 2¹⁷ = 997437512453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77615182 + ... + 77628031.

It is an arithmetic number, because the mean of its divisors is an integer number (103469602131).

Almost surely, 2^997437643525 is an apocalyptic number.

It is an amenable number.

997437643525 is a deficient number, since it is larger than the sum of its proper divisors (244197582047).

997437643525 is a wasteful number, since it uses less digits than its factorization.

997437643525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155243480 (or 155243475 counting only the distinct ones).

The product of its digits is 171460800, while the sum is 64.

The spelling of 997437643525 in words is "nine hundred ninety-seven billion, four hundred thirty-seven million, six hundred forty-three thousand, five hundred twenty-five".