7121891 has 8 divisors (see below), whose sum is σ = 8187744. Its totient is φ = 6068160.

The previous prime is 7121879. The next prime is 7121921. The reversal of 7121891 is 1981217.

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

It is a de Polignac number, because none of the positive numbers 2^k-7121891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7121801) 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, 1730 + ... + 4151.

It is an arithmetic number, because the mean of its divisors is an integer number (1023468).

Almost surely, 2^7121891 is an apocalyptic number.

7121891 is a deficient number, since it is larger than the sum of its proper divisors (1065853).

7121891 is a wasteful number, since it uses less digits than its factorization.

7121891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6061.

The product of its digits is 1008, while the sum is 29.

The square root of 7121891 is about 2668.6871304070. The cubic root of 7121891 is about 192.3970642112.

The spelling of 7121891 in words is "seven million, one hundred twenty-one thousand, eight hundred ninety-one".