21059889 has 8 divisors (see below), whose sum is σ = 29731680. Its totient is φ = 13214016.

The previous prime is 21059879. The next prime is 21059911. The reversal of 21059889 is 98895012.

It is a happy number.

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

It is not a de Polignac number, because 21059889 - 2⁷ = 21059761 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21059889.

It is not an unprimeable number, because it can be changed into a prime (21059849) 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, 206419 + ... + 206520.

It is an arithmetic number, because the mean of its divisors is an integer number (3716460).

Almost surely, 2^21059889 is an apocalyptic number.

It is an amenable number.

21059889 is a deficient number, since it is larger than the sum of its proper divisors (8671791).

21059889 is a wasteful number, since it uses less digits than its factorization.

21059889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412959.

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 21059889 is about 4589.1054683892. The cubic root of 21059889 is about 276.1544373022.

The spelling of 21059889 in words is "twenty-one million, fifty-nine thousand, eight hundred eighty-nine".