997501657 has 2 divisors, whose sum is σ = 997501658. Its totient is φ = 997501656.

The previous prime is 997501643. The next prime is 997501709. The reversal of 997501657 is 756105799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 805651456 + 191850201 = 28384^2 + 13851^2 .

It is a cyclic number.

It is not a de Polignac number, because 997501657 - 2¹⁹ = 996977369 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 997501657.

It is not a weakly prime, because it can be changed into another prime (997501607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498750828 + 498750829.

It is an arithmetic number, because the mean of its divisors is an integer number (498750829).

Almost surely, 2^997501657 is an apocalyptic number.

It is an amenable number.

997501657 is a deficient number, since it is larger than the sum of its proper divisors (1).

997501657 is an equidigital number, since it uses as much as digits as its factorization.

997501657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 595350, while the sum is 49.

The square root of 997501657 is about 31583.2496269779. The cubic root of 997501657 is about 999.1665245116.

The spelling of 997501657 in words is "nine hundred ninety-seven million, five hundred one thousand, six hundred fifty-seven".