21143320040 has 64 divisors (see below), whose sum is σ = 48295906560. Its totient is φ = 8328983040.

The previous prime is 21143320039. The next prime is 21143320043. The reversal of 21143320040 is 4002334112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21143319994 and 21143320021.

It is not an unprimeable number, because it can be changed into a prime (21143320043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2930117 + ... + 2937323.

It is an arithmetic number, because the mean of its divisors is an integer number (754623540).

Almost surely, 2^21143320040 is an apocalyptic number.

21143320040 is a gapful number since it is divisible by the number (20) 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 21143320040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24147953280).

21143320040 is an abundant number, since it is smaller than the sum of its proper divisors (27152586520).

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

21143320040 is a wasteful number, since it uses less digits than its factorization.

21143320040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8322 (or 8318 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21143320040 its reverse (4002334112), we get a palindrome (25145654152).

The spelling of 21143320040 in words is "twenty-one billion, one hundred forty-three million, three hundred twenty thousand, forty".