999874921 has 2 divisors, whose sum is σ = 999874922. Its totient is φ = 999874920.

The previous prime is 999874901. The next prime is 999874979. The reversal of 999874921 is 129478999.

It is an a-pointer prime, because the next prime (999874979) can be obtained adding 999874921 to its sum of digits (58).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 699338025 + 300536896 = 26445^2 + 17336^2 .

It is a cyclic number.

It is not a de Polignac number, because 999874921 - 2⁷ = 999874793 is a prime.

It is not a weakly prime, because it can be changed into another prime (999874901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499937460 + 499937461.

It is an arithmetic number, because the mean of its divisors is an integer number (499937461).

Almost surely, 2^999874921 is an apocalyptic number.

It is an amenable number.

999874921 is a deficient number, since it is larger than the sum of its proper divisors (1).

999874921 is an equidigital number, since it uses as much as digits as its factorization.

999874921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 58.

The square root of 999874921 is about 31620.7988672013. The cubic root of 999874921 is about 999.9583052616.

The spelling of 999874921 in words is "nine hundred ninety-nine million, eight hundred seventy-four thousand, nine hundred twenty-one".