7991151 has 16 divisors (see below), whose sum is σ = 12305664. Its totient is φ = 4518144.

The previous prime is 7991147. The next prime is 7991167. The reversal of 7991151 is 1511997.

7991151 = 749² + 750² + ... + 762².

It is a happy number.

It is not a de Polignac number, because 7991151 - 2² = 7991147 is a prime.

7991151 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7991101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76 + ... + 3998.

It is an arithmetic number, because the mean of its divisors is an integer number (769104).

Almost surely, 2^7991151 is an apocalyptic number.

7991151 is a deficient number, since it is larger than the sum of its proper divisors (4314513).

7991151 is a wasteful number, since it uses less digits than its factorization.

7991151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4030.

The product of its digits is 2835, while the sum is 33.

The square root of 7991151 is about 2826.8623949531. The cubic root of 7991151 is about 199.9262311274.

The spelling of 7991151 in words is "seven million, nine hundred ninety-one thousand, one hundred fifty-one".