21251063243630 has 32 divisors (see below), whose sum is σ = 41758119900288. Its totient is φ = 7722333556000.

The previous prime is 21251063243581. The next prime is 21251063243633. The reversal of 21251063243630 is 3634236015212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251063243633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66412232 + ... + 66731451.

It is an arithmetic number, because the mean of its divisors is an integer number (1304941246884).

Almost surely, 2^{21251063243630} is an apocalyptic number.

21251063243630 is a deficient number, since it is larger than the sum of its proper divisors (20507056656658).

21251063243630 is a wasteful number, since it uses less digits than its factorization.

21251063243630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133145152.

The product of its (nonzero) digits is 155520, while the sum is 38.

Adding to 21251063243630 its reverse (3634236015212), we get a palindrome (24885299258842).

The spelling of 21251063243630 in words is "twenty-one trillion, two hundred fifty-one billion, sixty-three million, two hundred forty-three thousand, six hundred thirty".