191649253209 has 16 divisors (see below), whose sum is σ = 258186933312. Its totient is φ = 126439077888.

The previous prime is 191649253199. The next prime is 191649253261. The reversal of 191649253209 is 902352946191.

It is not a de Polignac number, because 191649253209 - 2¹¹ = 191649251161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (191649203209) 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, 6676642 + ... + 6705284.

It is an arithmetic number, because the mean of its divisors is an integer number (16136683332).

Almost surely, 2^191649253209 is an apocalyptic number.

It is an amenable number.

191649253209 is a deficient number, since it is larger than the sum of its proper divisors (66537680103).

191649253209 is a wasteful number, since it uses less digits than its factorization.

191649253209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51736.

The product of its (nonzero) digits is 1049760, while the sum is 51.

The spelling of 191649253209 in words is "one hundred ninety-one billion, six hundred forty-nine million, two hundred fifty-three thousand, two hundred nine".