999913021 has 4 divisors (see below), whose sum is σ = 1058731452. Its totient is φ = 941094592.

The previous prime is 999913009. The next prime is 999913039. The reversal of 999913021 is 120319999.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 277056025 + 722856996 = 16645^2 + 26886^2 .

It is a cyclic number.

It is not a de Polignac number, because 999913021 - 2⁵ = 999912989 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 (999913921) 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 3 ways as a sum of consecutive naturals, for example, 29409190 + ... + 29409223.

It is an arithmetic number, because the mean of its divisors is an integer number (264682863).

Almost surely, 2^999913021 is an apocalyptic number.

It is an amenable number.

999913021 is a deficient number, since it is larger than the sum of its proper divisors (58818431).

999913021 is a wasteful number, since it uses less digits than its factorization.

999913021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58818430.

The product of its (nonzero) digits is 39366, while the sum is 43.

The square root of 999913021 is about 31621.4013130348. The cubic root of 999913021 is about 999.9710061594.

The spelling of 999913021 in words is "nine hundred ninety-nine million, nine hundred thirteen thousand, twenty-one".