21492340 has 12 divisors (see below), whose sum is σ = 45133956. Its totient is φ = 8596928.

The previous prime is 21492259. The next prime is 21492349. The reversal of 21492340 is 4329412.

It can be written as a sum of positive squares in 2 ways, for example, as 4153444 + 17338896 = 2038^2 + 4164^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21492349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 537289 + ... + 537328.

It is an arithmetic number, because the mean of its divisors is an integer number (3761163).

Almost surely, 2^21492340 is an apocalyptic number.

21492340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21492340 is an abundant number, since it is smaller than the sum of its proper divisors (23641616).

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

21492340 is a wasteful number, since it uses less digits than its factorization.

21492340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1074626 (or 1074624 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21492340 is about 4635.9831751205. The cubic root of 21492340 is about 278.0318615036.

It can be divided in two parts, 2149 and 2340, that added together give a square (4489 = 67²).

The spelling of 21492340 in words is "twenty-one million, four hundred ninety-two thousand, three hundred forty".