191619657397 has 12 divisors (see below), whose sum is σ = 230590863180. Its totient is φ = 158581784256.

The previous prime is 191619657347. The next prime is 191619657479. The reversal of 191619657397 is 793756916191.

It can be written as a sum of positive squares in 2 ways, for example, as 73095070321 + 118524587076 = 270361^2 + 344274^2 .

It is not a de Polignac number, because 191619657397 - 2¹⁵ = 191619624629 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 (191619657347) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67422808 + ... + 67425649.

It is an arithmetic number, because the mean of its divisors is an integer number (19215905265).

Almost surely, 2^191619657397 is an apocalyptic number.

It is an amenable number.

191619657397 is a deficient number, since it is larger than the sum of its proper divisors (38971205783).

191619657397 is a wasteful number, since it uses less digits than its factorization.

191619657397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134848500 (or 134848493 counting only the distinct ones).

The product of its digits is 19289340, while the sum is 64.

The spelling of 191619657397 in words is "one hundred ninety-one billion, six hundred nineteen million, six hundred fifty-seven thousand, three hundred ninety-seven".