21324156 has 96 divisors (see below), whose sum is σ = 61931520. Its totient is φ = 5572800.

The previous prime is 21324143. The next prime is 21324161. The reversal of 21324156 is 65142312.

It is a super-2 number, since 2×21324156² = 909439258224672, which contains 22 as substring.

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, 49261 + ... + 49691.

It is an arithmetic number, because the mean of its divisors is an integer number (645120).

Almost surely, 2^21324156 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 21324156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30965760).

21324156 is an abundant number, since it is smaller than the sum of its proper divisors (40607364).

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

21324156 is a wasteful number, since it uses less digits than its factorization.

21324156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 493 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 21324156 is about 4617.8085711731. The cubic root of 21324156 is about 277.3047339889.

Adding to 21324156 its reverse (65142312), we get a palindrome (86466468).

The spelling of 21324156 in words is "twenty-one million, three hundred twenty-four thousand, one hundred fifty-six".