997859521 has 8 divisors (see below), whose sum is σ = 1032649920. Its totient is φ = 963094608.

The previous prime is 997859477. The next prime is 997859543. The reversal of 997859521 is 125958799.

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

It is a cyclic number.

It is not a de Polignac number, because 997859521 - 2²³ = 989470913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997859581) 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, 108900 + ... + 117706.

It is an arithmetic number, because the mean of its divisors is an integer number (129081240).

Almost surely, 2^997859521 is an apocalyptic number.

It is an amenable number.

997859521 is a deficient number, since it is larger than the sum of its proper divisors (34790399).

997859521 is a wasteful number, since it uses less digits than its factorization.

997859521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12743.

The product of its digits is 2041200, while the sum is 55.

The square root of 997859521 is about 31588.9145270932. The cubic root of 997859521 is about 999.2859973215.

The spelling of 997859521 in words is "nine hundred ninety-seven million, eight hundred fifty-nine thousand, five hundred twenty-one".