991846651 has 4 divisors (see below), whose sum is σ = 992540232. Its totient is φ = 991153072.

The previous prime is 991846649. The next prime is 991846727. The reversal of 991846651 is 156648199.

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 991846651 - 2¹ = 991846649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 991846595 and 991846604.

It is not an unprimeable number, because it can be changed into a prime (991846601) 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, 344641 + ... + 347506.

It is an arithmetic number, because the mean of its divisors is an integer number (248135058).

Almost surely, 2^991846651 is an apocalyptic number.

991846651 is a deficient number, since it is larger than the sum of its proper divisors (693581).

991846651 is a wasteful number, since it uses less digits than its factorization.

991846651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693580.

The product of its digits is 466560, while the sum is 49.

The square root of 991846651 is about 31493.5969841490. The cubic root of 991846651 is about 997.2747970151.

The spelling of 991846651 in words is "nine hundred ninety-one million, eight hundred forty-six thousand, six hundred fifty-one".