21455005223240 has 16 divisors (see below), whose sum is σ = 48273761752380. Its totient is φ = 8582002089280.

The previous prime is 21455005223227. The next prime is 21455005223261. The reversal of 21455005223240 is 4232250055412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20938110369124 + 516894854116 = 4575818^2 + 718954^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21455005223240.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268187565251 + ... + 268187565330.

Almost surely, 2^{21455005223240} is an apocalyptic number.

21455005223240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21455005223240 is an abundant number, since it is smaller than the sum of its proper divisors (26818756529140).

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

21455005223240 is a wasteful number, since it uses less digits than its factorization.

21455005223240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536375130592 (or 536375130588 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 35.

Adding to 21455005223240 its reverse (4232250055412), we get a palindrome (25687255278652).

The spelling of 21455005223240 in words is "twenty-one trillion, four hundred fifty-five billion, five million, two hundred twenty-three thousand, two hundred forty".