999919421 has 4 divisors (see below), whose sum is σ = 999996000. Its totient is φ = 999842844.

The previous prime is 999919399. The next prime is 999919423. The reversal of 999919421 is 124919999.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 124919999 = 2671 ⋅46769.

It is a cyclic number.

It is not a de Polignac number, because 999919421 - 2²² = 995725117 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 (999919423) 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, 13241 + ... + 46638.

It is an arithmetic number, because the mean of its divisors is an integer number (249999000).

Almost surely, 2^999919421 is an apocalyptic number.

It is an amenable number.

999919421 is a deficient number, since it is larger than the sum of its proper divisors (76579).

999919421 is a wasteful number, since it uses less digits than its factorization.

999919421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76578.

The product of its digits is 472392, while the sum is 53.

The square root of 999919421 is about 31621.5025101591. The cubic root of 999919421 is about 999.9731396119.

The spelling of 999919421 in words is "nine hundred ninety-nine million, nine hundred nineteen thousand, four hundred twenty-one".