21433857 has 8 divisors (see below), whose sum is σ = 29275680. Its totient is φ = 13940640.

The previous prime is 21433831. The next prime is 21433859. The reversal of 21433857 is 75833412.

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

It is not a de Polignac number, because 21433857 - 2¹⁰ = 21432833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21433859) 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, 87007 + ... + 87252.

It is an arithmetic number, because the mean of its divisors is an integer number (3659460).

Almost surely, 2^21433857 is an apocalyptic number.

It is an amenable number.

21433857 is a deficient number, since it is larger than the sum of its proper divisors (7841823).

21433857 is a wasteful number, since it uses less digits than its factorization.

21433857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174303.

The product of its digits is 20160, while the sum is 33.

The square root of 21433857 is about 4629.6713706266. The cubic root of 21433857 is about 277.7794474151.

The spelling of 21433857 in words is "twenty-one million, four hundred thirty-three thousand, eight hundred fifty-seven".