999751121 has 2 divisors, whose sum is σ = 999751122. Its totient is φ = 999751120.

The previous prime is 999751091. The next prime is 999751157. The reversal of 999751121 is 121157999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 544568896 + 455182225 = 23336^2 + 21335^2 .

It is a cyclic number.

It is not a de Polignac number, because 999751121 - 2⁶ = 999751057 is a prime.

It is not a weakly prime, because it can be changed into another prime (999751721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499875560 + 499875561.

It is an arithmetic number, because the mean of its divisors is an integer number (499875561).

Almost surely, 2^999751121 is an apocalyptic number.

It is an amenable number.

999751121 is a deficient number, since it is larger than the sum of its proper divisors (1).

999751121 is an equidigital number, since it uses as much as digits as its factorization.

999751121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51030, while the sum is 44.

The square root of 999751121 is about 31618.8412343021. The cubic root of 999751121 is about 999.9170334501.

The spelling of 999751121 in words is "nine hundred ninety-nine million, seven hundred fifty-one thousand, one hundred twenty-one".