21152222251 has 8 divisors (see below), whose sum is σ = 22076943264. Its totient is φ = 20227922880.

The previous prime is 21152222183. The next prime is 21152222263. The reversal of 21152222251 is 15222225112.

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

It is a cyclic number.

It is not a de Polignac number, because 21152222251 - 2¹¹ = 21152220203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21152222551) by changing a digit.

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, 660 + ... + 205681.

It is an arithmetic number, because the mean of its divisors is an integer number (2759617908).

Almost surely, 2^21152222251 is an apocalyptic number.

21152222251 is a deficient number, since it is larger than the sum of its proper divisors (924721013).

21152222251 is a wasteful number, since it uses less digits than its factorization.

21152222251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210821.

The product of its digits is 1600, while the sum is 25.

Adding to 21152222251 its reverse (15222225112), we get a palindrome (36374447363).

The spelling of 21152222251 in words is "twenty-one billion, one hundred fifty-two million, two hundred twenty-two thousand, two hundred fifty-one".