21489258 has 32 divisors (see below), whose sum is σ = 52009344. Its totient is φ = 5778432.

The previous prime is 21489257. The next prime is 21489271. The reversal of 21489258 is 85298412.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21489257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14335 + ... + 15762.

It is an arithmetic number, because the mean of its divisors is an integer number (1625292).

Almost surely, 2^21489258 is an apocalyptic number.

21489258 is an abundant number, since it is smaller than the sum of its proper divisors (30520086).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21489258 is a wasteful number, since it uses less digits than its factorization.

21489258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30126.

The product of its digits is 46080, while the sum is 39.

The square root of 21489258 is about 4635.6507633772. The cubic root of 21489258 is about 278.0185709520.

The spelling of 21489258 in words is "twenty-one million, four hundred eighty-nine thousand, two hundred fifty-eight".