21352234440 has 32 divisors (see below), whose sum is σ = 64056703680. Its totient is φ = 5693929152.

The previous prime is 21352234439. The next prime is 21352234457. The reversal of 21352234440 is 4443225312.

It is a super-2 number, since 2×21352234440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21352234398 and 21352234407.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88967524 + ... + 88967763.

It is an arithmetic number, because the mean of its divisors is an integer number (2001771990).

Almost surely, 2^21352234440 is an apocalyptic number.

21352234440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21352234440 is an abundant number, since it is smaller than the sum of its proper divisors (42704469240).

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

21352234440 is a wasteful number, since it uses less digits than its factorization.

21352234440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177935301 (or 177935297 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 30.

Adding to 21352234440 its reverse (4443225312), we get a palindrome (25795459752).

The spelling of 21352234440 in words is "twenty-one billion, three hundred fifty-two million, two hundred thirty-four thousand, four hundred forty".