21000324440 has 16 divisors (see below), whose sum is σ = 47250730080. Its totient is φ = 8400129760.

The previous prime is 21000324419. The next prime is 21000324463. The reversal of 21000324440 is 4442300012.

It is a super-2 number, since 2×21000324440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262504016 + ... + 262504095.

It is an arithmetic number, because the mean of its divisors is an integer number (2953170630).

Almost surely, 2^21000324440 is an apocalyptic number.

21000324440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000324440 is an abundant number, since it is smaller than the sum of its proper divisors (26250405640).

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

21000324440 is a wasteful number, since it uses less digits than its factorization.

21000324440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525008122 (or 525008118 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21000324440 its reverse (4442300012), we get a palindrome (25442624452).

The spelling of 21000324440 in words is "twenty-one billion, three hundred twenty-four thousand, four hundred forty".