21403202340440 has 128 divisors (see below), whose sum is σ = 50027094331200. Its totient is φ = 8234375086080.

The previous prime is 21403202340431. The next prime is 21403202340503. The reversal of 21403202340440 is 4404320230412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 123231260 + ... + 123404820.

Almost surely, 2^{21403202340440} is an apocalyptic number.

21403202340440 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 21403202340440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25013547165600).

21403202340440 is an abundant number, since it is smaller than the sum of its proper divisors (28623891990760).

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

21403202340440 is a wasteful number, since it uses less digits than its factorization.

21403202340440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174565 (or 174561 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 21403202340440 its reverse (4404320230412), we get a palindrome (25807522570852).

The spelling of 21403202340440 in words is "twenty-one trillion, four hundred three billion, two hundred two million, three hundred forty thousand, four hundred forty".