209139001391 has 16 divisors (see below), whose sum is σ = 216316459200. Its totient is φ = 202042874880.

The previous prime is 209139001367. The next prime is 209139001433. The reversal of 209139001391 is 193100931902.

It is not a de Polignac number, because 209139001391 - 2²² = 209134807087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209139001091) 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, 18523550 + ... + 18534836.

It is an arithmetic number, because the mean of its divisors is an integer number (13519778700).

Almost surely, 2^209139001391 is an apocalyptic number.

209139001391 is a deficient number, since it is larger than the sum of its proper divisors (7177457809).

209139001391 is a wasteful number, since it uses less digits than its factorization.

209139001391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14834.

The product of its (nonzero) digits is 13122, while the sum is 38.

The spelling of 209139001391 in words is "two hundred nine billion, one hundred thirty-nine million, one thousand, three hundred ninety-one".