9915399491 has 4 divisors (see below), whose sum is σ = 9921712584. Its totient is φ = 9909086400.

The previous prime is 9915399467. The next prime is 9915399493. The reversal of 9915399491 is 1949935199.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9915399491 - 2⁶ = 9915399427 is a prime.

It is a super-2 number, since 2×9915399491² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9915399491.

It is not an unprimeable number, because it can be changed into a prime (9915399493) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3154190 + ... + 3157331.

It is an arithmetic number, because the mean of its divisors is an integer number (2480428146).

Almost surely, 2^9915399491 is an apocalyptic number.

9915399491 is a deficient number, since it is larger than the sum of its proper divisors (6313093).

9915399491 is a wasteful number, since it uses less digits than its factorization.

9915399491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6313092.

The product of its digits is 3542940, while the sum is 59.

The square root of 9915399491 is about 99576.0989946885. The cubic root of 9915399491 is about 2148.3419335366.

The spelling of 9915399491 in words is "nine billion, nine hundred fifteen million, three hundred ninety-nine thousand, four hundred ninety-one".