91240197399 has 12 divisors (see below), whose sum is σ = 141929196136. Its totient is φ = 56147813712.

The previous prime is 91240197371. The next prime is 91240197437. The reversal of 91240197399 is 99379104219.

It is a happy number.

91240197399 is a `hidden beast` number, since 9 + 1 + 240 + 1 + 9 + 7 + 399 = 666.

It is not a de Polignac number, because 91240197399 - 2¹⁷ = 91240066327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91240197319) 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, 389915257 + ... + 389915490.

Almost surely, 2^91240197399 is an apocalyptic number.

91240197399 is a deficient number, since it is larger than the sum of its proper divisors (50688998737).

91240197399 is a wasteful number, since it uses less digits than its factorization.

91240197399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779830766 (or 779830763 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The spelling of 91240197399 in words is "ninety-one billion, two hundred forty million, one hundred ninety-seven thousand, three hundred ninety-nine".