206997640 has 16 divisors (see below), whose sum is σ = 465744780. Its totient is φ = 82799040.

The previous prime is 206997629. The next prime is 206997641. The reversal of 206997640 is 46799602.

It can be written as a sum of positive squares in 2 ways, for example, as 181656484 + 25341156 = 13478^2 + 5034^2 .

It is not an unprimeable number, because it can be changed into a prime (206997641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2587431 + ... + 2587510.

Almost surely, 2^206997640 is an apocalyptic number.

206997640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206997640 is an abundant number, since it is smaller than the sum of its proper divisors (258747140).

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

206997640 is a wasteful number, since it uses less digits than its factorization.

206997640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5174952 (or 5174948 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 206997640 is about 14387.4125540349. The cubic root of 206997640 is about 591.5459218880.

The spelling of 206997640 in words is "two hundred six million, nine hundred ninety-seven thousand, six hundred forty".