21293140 has 24 divisors (see below), whose sum is σ = 48781152. Its totient is φ = 7742880.

The previous prime is 21293131. The next prime is 21293141. The reversal of 21293140 is 4139212.

It is a super-2 number, since 2×21293140² = 906795622119200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21293141) 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, 48174 + ... + 48613.

It is an arithmetic number, because the mean of its divisors is an integer number (2032548).

Almost surely, 2^21293140 is an apocalyptic number.

21293140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21293140 is an abundant number, since it is smaller than the sum of its proper divisors (27488012).

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

21293140 is a wasteful number, since it uses less digits than its factorization.

21293140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96807 (or 96805 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21293140 is about 4614.4490462026. The cubic root of 21293140 is about 277.1702221080.

The spelling of 21293140 in words is "twenty-one million, two hundred ninety-three thousand, one hundred forty".