21033255240 has 48 divisors (see below), whose sum is σ = 68358080700. Its totient is φ = 5608867968.

The previous prime is 21033255239. The next prime is 21033255311. The reversal of 21033255240 is 4255233012.

It is a happy number.

21033255240 is a `hidden beast` number, since 2 + 103 + 3 + 2 + 552 + 4 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18735586884 + 2297668356 = 136878^2 + 47934^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29212495 + ... + 29213214.

Almost surely, 2^21033255240 is an apocalyptic number.

21033255240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21033255240 is an abundant number, since it is smaller than the sum of its proper divisors (47324825460).

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

21033255240 is a wasteful number, since it uses less digits than its factorization.

21033255240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58425726 (or 58425719 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 27.

Adding to 21033255240 its reverse (4255233012), we get a palindrome (25288488252).

The spelling of 21033255240 in words is "twenty-one billion, thirty-three million, two hundred fifty-five thousand, two hundred forty".