7121975691 has 16 divisors (see below), whose sum is σ = 9915365376. Its totient is φ = 4538557056.

The previous prime is 7121975671. The next prime is 7121975779. The reversal of 7121975691 is 1965791217.

It is not a de Polignac number, because 7121975691 - 2¹⁰ = 7121974667 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7121975691.

It is not an unprimeable number, because it can be changed into a prime (7121975621) 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, 73926 + ... + 140388.

It is an arithmetic number, because the mean of its divisors is an integer number (619710336).

Almost surely, 2^7121975691 is an apocalyptic number.

7121975691 is a deficient number, since it is larger than the sum of its proper divisors (2793389685).

7121975691 is a wasteful number, since it uses less digits than its factorization.

7121975691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68042.

The product of its digits is 238140, while the sum is 48.

The square root of 7121975691 is about 84391.7987188329. The cubic root of 7121975691 is about 1923.9782684738.

The spelling of 7121975691 in words is "seven billion, one hundred twenty-one million, nine hundred seventy-five thousand, six hundred ninety-one".