992157991 has 4 divisors (see below), whose sum is σ = 1082354184. Its totient is φ = 901961800.

The previous prime is 992157931. The next prime is 992158019. The reversal of 992157991 is 199751299.

It is a happy number.

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 992157991 - 2¹¹ = 992155943 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 (992157911) 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, 45098080 + ... + 45098101.

It is an arithmetic number, because the mean of its divisors is an integer number (270588546).

Almost surely, 2^992157991 is an apocalyptic number.

992157991 is a deficient number, since it is larger than the sum of its proper divisors (90196193).

992157991 is a wasteful number, since it uses less digits than its factorization.

992157991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90196192.

The product of its digits is 459270, while the sum is 52.

The square root of 992157991 is about 31498.5395058247. The cubic root of 992157991 is about 997.3791340626.

The spelling of 992157991 in words is "nine hundred ninety-two million, one hundred fifty-seven thousand, nine hundred ninety-one".