997569421 has 2 divisors, whose sum is σ = 997569422. Its totient is φ = 997569420.

The previous prime is 997569403. The next prime is 997569431. The reversal of 997569421 is 124965799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 729756196 + 267813225 = 27014^2 + 16365^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997569421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997569431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498784710 + 498784711.

It is an arithmetic number, because the mean of its divisors is an integer number (498784711).

Almost surely, 2^997569421 is an apocalyptic number.

It is an amenable number.

997569421 is a deficient number, since it is larger than the sum of its proper divisors (1).

997569421 is an equidigital number, since it uses as much as digits as its factorization.

997569421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1224720, while the sum is 52.

The square root of 997569421 is about 31584.3223926048. The cubic root of 997569421 is about 999.1891496995.

The spelling of 997569421 in words is "nine hundred ninety-seven million, five hundred sixty-nine thousand, four hundred twenty-one".