997815 has 64 divisors (see below), whose sum is σ = 2128896. Its totient is φ = 387072.

The previous prime is 997813. The next prime is 997877. The reversal of 997815 is 518799.

It is a happy number.

It is not a de Polignac number, because 997815 - 2¹ = 997813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997811) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23184 + ... + 23226.

It is an arithmetic number, because the mean of its divisors is an integer number (33264).

2⁹⁹⁷⁸¹⁵ is an apocalyptic number.

997815 is an abundant number, since it is smaller than the sum of its proper divisors (1131081).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

997815 is a wasteful number, since it uses less digits than its factorization.

997815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88.

The product of its digits is 22680, while the sum is 39.

The square root of 997815 is about 998.9069025690. The cubic root of 997815 is about 99.9271135552.

The spelling of 997815 in words is "nine hundred ninety-seven thousand, eight hundred fifteen".