21251051335 has 8 divisors (see below), whose sum is σ = 26323883136. Its totient is φ = 16452426720.

The previous prime is 21251051321. The next prime is 21251051377. The reversal of 21251051335 is 53315015212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21251051335 - 2¹⁹ = 21250527047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68551624 + ... + 68551933.

It is an arithmetic number, because the mean of its divisors is an integer number (3290485392).

Almost surely, 2^21251051335 is an apocalyptic number.

21251051335 is a deficient number, since it is larger than the sum of its proper divisors (5072831801).

21251051335 is a wasteful number, since it uses less digits than its factorization.

21251051335 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137103593.

The product of its (nonzero) digits is 4500, while the sum is 28.

Adding to 21251051335 its reverse (53315015212), we get a palindrome (74566066547).

The spelling of 21251051335 in words is "twenty-one billion, two hundred fifty-one million, fifty-one thousand, three hundred thirty-five".