21930324 has 48 divisors (see below), whose sum is σ = 55422528. Its totient is φ = 6709248.

The previous prime is 21930283. The next prime is 21930329. The reversal of 21930324 is 42303912.

It is a super-2 number, since 2×21930324² = 961878221489952, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21930294 and 21930303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21930329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39819 + ... + 40365.

It is an arithmetic number, because the mean of its divisors is an integer number (1154636).

Almost surely, 2^21930324 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 21930324, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27711264).

21930324 is an abundant number, since it is smaller than the sum of its proper divisors (33492204).

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

21930324 is a wasteful number, since it uses less digits than its factorization.

21930324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824 (or 822 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 21930324 is about 4682.9823830546. The cubic root of 21930324 is about 279.9078097857.

The spelling of 21930324 in words is "twenty-one million, nine hundred thirty thousand, three hundred twenty-four".