209006931 has 16 divisors (see below), whose sum is σ = 324497664. Its totient is φ = 117178464.

The previous prime is 209006927. The next prime is 209006939. The reversal of 209006931 is 139600902.

209006931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 209006931 - 2² = 209006927 is a prime.

It is a super-2 number, since 2×209006931² = 87367794412077522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (209006939) 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, 92781 + ... + 95006.

It is an arithmetic number, because the mean of its divisors is an integer number (20281104).

Almost surely, 2^209006931 is an apocalyptic number.

209006931 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

209006931 is a deficient number, since it is larger than the sum of its proper divisors (115490733).

209006931 is a wasteful number, since it uses less digits than its factorization.

209006931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187850.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 209006931 is about 14457.0720064611. The cubic root of 209006931 is about 593.4537740674.

The spelling of 209006931 in words is "two hundred nine million, six thousand, nine hundred thirty-one".