21489659 has 8 divisors (see below), whose sum is σ = 22709760. Its totient is φ = 20293416.

The previous prime is 21489653. The next prime is 21489661. The reversal of 21489659 is 95698412.

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

It is a cyclic number.

It is not a de Polignac number, because 21489659 - 2²⁴ = 4712443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21489653) 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, 4097 + ... + 7730.

It is an arithmetic number, because the mean of its divisors is an integer number (2838720).

Almost surely, 2^21489659 is an apocalyptic number.

21489659 is a deficient number, since it is larger than the sum of its proper divisors (1220101).

21489659 is a wasteful number, since it uses less digits than its factorization.

21489659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11929.

The product of its digits is 155520, while the sum is 44.

The square root of 21489659 is about 4635.6940149238. The cubic root of 21489659 is about 278.0203002618.

The spelling of 21489659 in words is "twenty-one million, four hundred eighty-nine thousand, six hundred fifty-nine".