7121691 has 24 divisors (see below), whose sum is σ = 11035440. Its totient is φ = 4409856.

The previous prime is 7121687. The next prime is 7121693. The reversal of 7121691 is 1961217.

It is not a de Polignac number, because 7121691 - 2² = 7121687 is a prime.

7121691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7121693) 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, 13356 + ... + 13878.

It is an arithmetic number, because the mean of its divisors is an integer number (459810).

Almost surely, 2^7121691 is an apocalyptic number.

7121691 is a deficient number, since it is larger than the sum of its proper divisors (3913749).

7121691 is a wasteful number, since it uses less digits than its factorization.

7121691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 635 (or 632 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 7121691 is about 2668.6496585352. The cubic root of 7121691 is about 192.3952632020.

The spelling of 7121691 in words is "seven million, one hundred twenty-one thousand, six hundred ninety-one".