21421659 has 8 divisors (see below), whose sum is σ = 32642560. Its totient is φ = 12240936.

The previous prime is 21421657. The next prime is 21421667. The reversal of 21421659 is 95612412.

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

It is not a de Polignac number, because 21421659 - 2¹ = 21421657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421657) 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, 510019 + ... + 510060.

It is an arithmetic number, because the mean of its divisors is an integer number (4080320).

Almost surely, 2^21421659 is an apocalyptic number.

21421659 is a deficient number, since it is larger than the sum of its proper divisors (11220901).

21421659 is a wasteful number, since it uses less digits than its factorization.

21421659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020089.

The product of its digits is 4320, while the sum is 30.

The square root of 21421659 is about 4628.3538110218. The cubic root of 21421659 is about 277.7267426893.

The spelling of 21421659 in words is "twenty-one million, four hundred twenty-one thousand, six hundred fifty-nine".