999413621 has 4 divisors (see below), whose sum is σ = 1004436000. Its totient is φ = 994391244.

The previous prime is 999413599. The next prime is 999413627. The reversal of 999413621 is 126314999.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 126314999 = 139 ⋅908741.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999413621 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 (999413627) 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, 2510891 + ... + 2511288.

It is an arithmetic number, because the mean of its divisors is an integer number (251109000).

Almost surely, 2^999413621 is an apocalyptic number.

It is an amenable number.

999413621 is a deficient number, since it is larger than the sum of its proper divisors (5022379).

999413621 is a wasteful number, since it uses less digits than its factorization.

999413621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5022378.

The product of its digits is 104976, while the sum is 44.

The square root of 999413621 is about 31613.5037760765. The cubic root of 999413621 is about 999.8045021164.

The spelling of 999413621 in words is "nine hundred ninety-nine million, four hundred thirteen thousand, six hundred twenty-one".