21063781250 has 42 divisors (see below), whose sum is σ = 39542247759. Its totient is φ = 8415250000.

The previous prime is 21063781247. The next prime is 21063781313. The reversal of 21063781250 is 5218736012.

It is a happy number.

It can be written as a sum of positive squares in 11 ways, for example, as 20740896289 + 322884961 = 144017^2 + 17969^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=102625.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21063781250.

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 25655840 + ... + 25656660.

Almost surely, 2^21063781250 is an apocalyptic number.

21063781250 is a deficient number, since it is larger than the sum of its proper divisors (18478466509).

21063781250 is an frugal number, since it uses more digits than its factorization.

21063781250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1674 (or 828 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The spelling of 21063781250 in words is "twenty-one billion, sixty-three million, seven hundred eighty-one thousand, two hundred fifty".