9997819 has 16 divisors (see below), whose sum is σ = 12005280. Its totient is φ = 8225280.

The previous prime is 9997817. The next prime is 9997829. The reversal of 9997819 is 9187999.

It is not a de Polignac number, because 9997819 - 2¹ = 9997817 is a prime.

It is a super-2 number, since 2×9997819² = 199912769513522, which contains 22 as substring.

It is a Duffinian number.

9997819 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9997817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3009 + ... + 5389.

It is an arithmetic number, because the mean of its divisors is an integer number (750330).

Almost surely, 2^9997819 is an apocalyptic number.

9997819 is a deficient number, since it is larger than the sum of its proper divisors (2007461).

9997819 is a wasteful number, since it uses less digits than its factorization.

9997819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2430.

The product of its digits is 367416, while the sum is 52.

The square root of 9997819 is about 3161.9327949847. The cubic root of 9997819 is about 215.4278051242.

It can be divided in two parts, 9997 and 819, that added together give a square (10816 = 104²).

The spelling of 9997819 in words is "nine million, nine hundred ninety-seven thousand, eight hundred nineteen".