21493000 has 32 divisors (see below), whose sum is σ = 50295960. Its totient is φ = 8596800.

The previous prime is 21492953. The next prime is 21493007. The reversal of 21493000 is 39412.

It can be written as a sum of positive squares in 4 ways, for example, as 2256004 + 19236996 = 1502^2 + 4386^2 .

It is not an unprimeable number, because it can be changed into a prime (21493007) 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, 9747 + ... + 11746.

Almost surely, 2^21493000 is an apocalyptic number.

21493000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21493000 is an abundant number, since it is smaller than the sum of its proper divisors (28802960).

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

21493000 is a wasteful number, since it uses less digits than its factorization.

21493000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21514 (or 21500 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21493000 is about 4636.0543568858. The cubic root of 21493000 is about 278.0347074656.

The spelling of 21493000 in words is "twenty-one million, four hundred ninety-three thousand".