20421322440 has 32 divisors (see below), whose sum is σ = 61263967680. Its totient is φ = 5445685952.

The previous prime is 20421322433. The next prime is 20421322459. The reversal of 20421322440 is 4422312402.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20421322440.

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, 85088724 + ... + 85088963.

It is an arithmetic number, because the mean of its divisors is an integer number (1914498990).

Almost surely, 2^20421322440 is an apocalyptic number.

20421322440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20421322440 is an abundant number, since it is smaller than the sum of its proper divisors (40842645240).

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

20421322440 is a wasteful number, since it uses less digits than its factorization.

20421322440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170177701 (or 170177697 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 20421322440 its reverse (4422312402), we get a palindrome (24843634842).

The spelling of 20421322440 in words is "twenty billion, four hundred twenty-one million, three hundred twenty-two thousand, four hundred forty".