21294140 has 48 divisors (see below), whose sum is σ = 51710400. Its totient is φ = 7214592.

The previous prime is 21294139. The next prime is 21294151. The reversal of 21294140 is 4149212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11606 + ... + 13314.

It is an arithmetic number, because the mean of its divisors is an integer number (1077300).

Almost surely, 2^21294140 is an apocalyptic number.

21294140 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 21294140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25855200).

21294140 is an abundant number, since it is smaller than the sum of its proper divisors (30416260).

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

21294140 is a wasteful number, since it uses less digits than its factorization.

21294140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1814 (or 1812 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21294140 is about 4614.5574002281. The cubic root of 21294140 is about 277.1745609997.

The spelling of 21294140 in words is "twenty-one million, two hundred ninety-four thousand, one hundred forty".