7139991 has 16 divisors (see below), whose sum is σ = 10083200. Its totient is φ = 4481568.

The previous prime is 7139971. The next prime is 7139999. The reversal of 7139991 is 1999317.

It is not a de Polignac number, because 7139991 - 2¹⁴ = 7123607 is a prime.

It is a Duffinian number.

7139991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7139999) 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, 12780 + ... + 13326.

It is an arithmetic number, because the mean of its divisors is an integer number (630200).

Almost surely, 2^7139991 is an apocalyptic number.

7139991 is a deficient number, since it is larger than the sum of its proper divisors (2943209).

7139991 is a wasteful number, since it uses less digits than its factorization.

7139991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798.

The product of its digits is 15309, while the sum is 39.

The square root of 7139991 is about 2672.0761590943. The cubic root of 7139991 is about 192.5599161328.

The spelling of 7139991 in words is "seven million, one hundred thirty-nine thousand, nine hundred ninety-one".