21432999 has 8 divisors (see below), whose sum is σ = 32659840. Its totient is φ = 12247416.

The previous prime is 21432991. The next prime is 21433051. The reversal of 21432999 is 99923412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21432999 - 2³ = 21432991 is a prime.

It is a super-2 number, since 2×21432999² = 918746892268002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 510289 + ... + 510330.

It is an arithmetic number, because the mean of its divisors is an integer number (4082480).

Almost surely, 2^21432999 is an apocalyptic number.

21432999 is a deficient number, since it is larger than the sum of its proper divisors (11226841).

21432999 is a wasteful number, since it uses less digits than its factorization.

21432999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020629.

The product of its digits is 34992, while the sum is 39.

The square root of 21432999 is about 4629.5787065348. The cubic root of 21432999 is about 277.7757408502.

The spelling of 21432999 in words is "twenty-one million, four hundred thirty-two thousand, nine hundred ninety-nine".