7915449991 has 4 divisors (see below), whose sum is σ = 7952964184. Its totient is φ = 7877935800.

The previous prime is 7915449947. The next prime is 7915450033. The reversal of 7915449991 is 1999445197.

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 7915449991 - 2³¹ = 5767966343 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 (7915449491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18756780 + ... + 18757201.

It is an arithmetic number, because the mean of its divisors is an integer number (1988241046).

Almost surely, 2^7915449991 is an apocalyptic number.

7915449991 is a deficient number, since it is larger than the sum of its proper divisors (37514193).

7915449991 is a wasteful number, since it uses less digits than its factorization.

7915449991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37514192.

The product of its digits is 3674160, while the sum is 58.

The square root of 7915449991 is about 88968.8147105490. The cubic root of 7915449991 is about 1992.9291972504.

The spelling of 7915449991 in words is "seven billion, nine hundred fifteen million, four hundred forty-nine thousand, nine hundred ninety-one".