21394488 has 32 divisors (see below), whose sum is σ = 53602560. Its totient is φ = 7116000.

The previous prime is 21394459. The next prime is 21394519. The reversal of 21394488 is 88449312.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17431 + ... + 18617.

It is an arithmetic number, because the mean of its divisors is an integer number (1675080).

Almost surely, 2^21394488 is an apocalyptic number.

It is an amenable number.

21394488 is an abundant number, since it is smaller than the sum of its proper divisors (32208072).

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

21394488 is a wasteful number, since it uses less digits than its factorization.

21394488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1947 (or 1943 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 21394488 is about 4625.4176027684. The cubic root of 21394488 is about 277.6092711457.

The spelling of 21394488 in words is "twenty-one million, three hundred ninety-four thousand, four hundred eighty-eight".