21253246425640 has 32 divisors (see below), whose sum is σ = 48986141155560. Its totient is φ = 8293949824000.

The previous prime is 21253246425511. The next prime is 21253246425659. The reversal of 21253246425640 is 4652464235212.

It can be written as a sum of positive squares in 4 ways, for example, as 4433913530596 + 16819332895044 = 2105686^2 + 4101138^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6479646661 + ... + 6479649940.

Almost surely, 2^{21253246425640} is an apocalyptic number.

21253246425640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21253246425640 is an abundant number, since it is smaller than the sum of its proper divisors (27732894729920).

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

21253246425640 is a wasteful number, since it uses less digits than its factorization.

21253246425640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12959296653 (or 12959296649 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 46.

The spelling of 21253246425640 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred forty-six million, four hundred twenty-five thousand, six hundred forty".