21826464 has 72 divisors (see below), whose sum is σ = 63010080. Its totient is φ = 6610560.

The previous prime is 21826463. The next prime is 21826481. The reversal of 21826464 is 46462812.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 (21826463) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10677 + ... + 12555.

It is an arithmetic number, because the mean of its divisors is an integer number (875140).

Almost surely, 2^21826464 is an apocalyptic number.

21826464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21826464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31505040).

21826464 is an abundant number, since it is smaller than the sum of its proper divisors (41183616).

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

21826464 is a wasteful number, since it uses less digits than its factorization.

21826464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1914 (or 1895 counting only the distinct ones).

The product of its digits is 18432, while the sum is 33.

The square root of 21826464 is about 4671.8801354487. The cubic root of 21826464 is about 279.4652378301.

It can be divided in two parts, 2182 and 6464, that added together give a triangular number (8646 = T₁₃₁).

The spelling of 21826464 in words is "twenty-one million, eight hundred twenty-six thousand, four hundred sixty-four".