1997455209 has 16 divisors (see below), whose sum is σ = 2807685120. Its totient is φ = 1261259280.

The previous prime is 1997455183. The next prime is 1997455211. The reversal of 1997455209 is 9025547991.

It is not a de Polignac number, because 1997455209 - 2¹⁹ = 1996930921 is a prime.

It is a super-2 number, since 2×1997455209² = 7979654623922467362, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1997455289) 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, 224119 + ... + 232860.

It is an arithmetic number, because the mean of its divisors is an integer number (175480320).

Almost surely, 2^1997455209 is an apocalyptic number.

It is an amenable number.

1997455209 is a deficient number, since it is larger than the sum of its proper divisors (810229911).

1997455209 is a wasteful number, since it uses less digits than its factorization.

1997455209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457060.

The product of its (nonzero) digits is 1020600, while the sum is 51.

The square root of 1997455209 is about 44692.8988654797. The cubic root of 1997455209 is about 1259.3864504653.

The spelling of 1997455209 in words is "one billion, nine hundred ninety-seven million, four hundred fifty-five thousand, two hundred nine".