206640997479 has 32 divisors (see below), whose sum is σ = 349920775680. Its totient is φ = 118062878400.

The previous prime is 206640997457. The next prime is 206640997517. The reversal of 206640997479 is 974799046602.

It is not a de Polignac number, because 206640997479 - 2²⁰ = 206639948903 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206640992479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1239099 + ... + 1395939.

It is an arithmetic number, because the mean of its divisors is an integer number (10935024240).

Almost surely, 2^206640997479 is an apocalyptic number.

206640997479 is a deficient number, since it is larger than the sum of its proper divisors (143279778201).

206640997479 is a wasteful number, since it uses less digits than its factorization.

206640997479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163828 (or 163822 counting only the distinct ones).

The product of its (nonzero) digits is 41150592, while the sum is 63.

The spelling of 206640997479 in words is "two hundred six billion, six hundred forty million, nine hundred ninety-seven thousand, four hundred seventy-nine".