990742791 has 4 divisors (see below), whose sum is σ = 1320990392. Its totient is φ = 660495192.

The previous prime is 990742769. The next prime is 990742807. The reversal of 990742791 is 197247099.

It is a happy number.

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

It is not a de Polignac number, because 990742791 - 2¹³ = 990734599 is a prime.

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 990742791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990742721) 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, 165123796 + ... + 165123801.

It is an arithmetic number, because the mean of its divisors is an integer number (330247598).

Almost surely, 2^990742791 is an apocalyptic number.

990742791 is a deficient number, since it is larger than the sum of its proper divisors (330247601).

990742791 is a wasteful number, since it uses less digits than its factorization.

990742791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330247600.

The product of its (nonzero) digits is 285768, while the sum is 48.

The square root of 990742791 is about 31476.0669557046. The cubic root of 990742791 is about 996.9046926242.

The spelling of 990742791 in words is "nine hundred ninety million, seven hundred forty-two thousand, seven hundred ninety-one".