21493080 has 128 divisors (see below), whose sum is σ = 81907200. Its totient is φ = 4910976.

The previous prime is 21493079. The next prime is 21493091. The reversal of 21493080 is 8039412.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6139 + ... + 8981.

It is an arithmetic number, because the mean of its divisors is an integer number (639900).

Almost surely, 2^21493080 is an apocalyptic number.

21493080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21493080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40953600).

21493080 is an abundant number, since it is smaller than the sum of its proper divisors (60414120).

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

21493080 is a wasteful number, since it uses less digits than its factorization.

21493080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2870 (or 2860 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21493080 is about 4636.0629849043. The cubic root of 21493080 is about 278.0350524267.

The spelling of 21493080 in words is "twenty-one million, four hundred ninety-three thousand, eighty".