7151991 has 24 divisors (see below), whose sum is σ = 12104064. Its totient is φ = 3714480.

The previous prime is 7151983. The next prime is 7152007. The reversal of 7151991 is 1991517.

It is a happy number.

It is not a de Polignac number, because 7151991 - 2³ = 7151983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

7151991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7151981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 595 + ... + 3828.

It is an arithmetic number, because the mean of its divisors is an integer number (504336).

Almost surely, 2^7151991 is an apocalyptic number.

7151991 is a deficient number, since it is larger than the sum of its proper divisors (4952073).

7151991 is a wasteful number, since it uses less digits than its factorization.

7151991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4451 (or 4444 counting only the distinct ones).

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

The square root of 7151991 is about 2674.3206614017. The cubic root of 7151991 is about 192.6677325936.

The spelling of 7151991 in words is "seven million, one hundred fifty-one thousand, nine hundred ninety-one".