991072651 has 8 divisors (see below), whose sum is σ = 1027138320. Its totient is φ = 955133088.

The previous prime is 991072609. The next prime is 991072717. The reversal of 991072651 is 156270199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 991072651 - 2²⁷ = 856854923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991072051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15376 + ... + 47101.

It is an arithmetic number, because the mean of its divisors is an integer number (128392290).

Almost surely, 2^991072651 is an apocalyptic number.

991072651 is a deficient number, since it is larger than the sum of its proper divisors (36065669).

991072651 is a wasteful number, since it uses less digits than its factorization.

991072651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63053.

The product of its (nonzero) digits is 34020, while the sum is 40.

The square root of 991072651 is about 31481.3063737832. The cubic root of 991072651 is about 997.0153175334.

The spelling of 991072651 in words is "nine hundred ninety-one million, seventy-two thousand, six hundred fifty-one".