21243498 has 8 divisors (see below), whose sum is σ = 42487008. Its totient is φ = 7081164.

The previous prime is 21243473. The next prime is 21243503. The reversal of 21243498 is 89434212.

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

21243498 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1770286 + ... + 1770297.

It is an arithmetic number, because the mean of its divisors is an integer number (5310876).

Almost surely, 2^21243498 is an apocalyptic number.

21243498 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21243498 is a wasteful number, since it uses less digits than its factorization.

21243498 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3540588.

The product of its digits is 13824, while the sum is 33.

The square root of 21243498 is about 4609.0669337730. The cubic root of 21243498 is about 276.9546598713.

The spelling of 21243498 in words is "twenty-one million, two hundred forty-three thousand, four hundred ninety-eight".