21432492 has 48 divisors (see below), whose sum is σ = 55910400. Its totient is φ = 7099920.

The previous prime is 21432473. The next prime is 21432493. The reversal of 21432492 is 29423412.

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21432493) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20109 + ... + 21147.

It is an arithmetic number, because the mean of its divisors is an integer number (1164800).

Almost surely, 2^21432492 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21432492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27955200).

21432492 is an abundant number, since it is smaller than the sum of its proper divisors (34477908).

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

21432492 is a wasteful number, since it uses less digits than its factorization.

21432492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243 (or 1235 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21432492 is about 4629.5239496086. The cubic root of 21432492 is about 277.7735505609.

The spelling of 21432492 in words is "twenty-one million, four hundred thirty-two thousand, four hundred ninety-two".