21402440000 has 70 divisors (see below), whose sum is σ = 53071194594. Its totient is φ = 8560960000.

The previous prime is 21402439997. The next prime is 21402440029. The reversal of 21402440000 is 4420412.

It can be written as a sum of positive squares in 5 ways, for example, as 11315853376 + 10086586624 = 106376^2 + 100432^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 227531 + ... + 307530.

Almost surely, 2^21402440000 is an apocalyptic number.

21402440000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21402440000 is an abundant number, since it is smaller than the sum of its proper divisors (31668754594).

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

21402440000 is an frugal number, since it uses more digits than its factorization.

21402440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535093 (or 535068 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

Adding to 21402440000 its reverse (4420412), we get a palindrome (21406860412).

The spelling of 21402440000 in words is "twenty-one billion, four hundred two million, four hundred forty thousand".