1909172213 has 24 divisors (see below), whose sum is σ = 2130928128. Its totient is φ = 1708454592.

The previous prime is 1909172207. The next prime is 1909172261. The reversal of 1909172213 is 3122719091.

It is not a de Polignac number, because 1909172213 - 2⁶ = 1909172149 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1909172203) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3144956 + ... + 3145562.

It is an arithmetic number, because the mean of its divisors is an integer number (88788672).

Almost surely, 2^1909172213 is an apocalyptic number.

1909172213 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1909172213 is a deficient number, since it is larger than the sum of its proper divisors (221755915).

1909172213 is a wasteful number, since it uses less digits than its factorization.

1909172213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1173 (or 1160 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 1909172213 is about 43694.0752619849. The cubic root of 1909172213 is about 1240.5521762506.

The spelling of 1909172213 in words is "one billion, nine hundred nine million, one hundred seventy-two thousand, two hundred thirteen".