75991121221 has 16 divisors (see below), whose sum is σ = 80676158976. Its totient is φ = 71460000000.

The previous prime is 75991121197. The next prime is 75991121333. The reversal of 75991121221 is 12212119957.

It is a cyclic number.

It is not a de Polignac number, because 75991121221 - 2⁷ = 75991121093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75991121021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199921 + ... + 438121.

It is an arithmetic number, because the mean of its divisors is an integer number (5042259936).

Almost surely, 2^75991121221 is an apocalyptic number.

It is an amenable number.

75991121221 is a deficient number, since it is larger than the sum of its proper divisors (4685037755).

75991121221 is a wasteful number, since it uses less digits than its factorization.

75991121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238524.

The product of its digits is 22680, while the sum is 40.

The spelling of 75991121221 in words is "seventy-five billion, nine hundred ninety-one million, one hundred twenty-one thousand, two hundred twenty-one".