21251403311 has 8 divisors (see below), whose sum is σ = 22177096704. Its totient is φ = 20325853240.

The previous prime is 21251403307. The next prime is 21251403317. The reversal of 21251403311 is 11330415212.

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 21251403311 - 2² = 21251403307 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251403317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 360650 + ... + 415416.

It is an arithmetic number, because the mean of its divisors is an integer number (2772137088).

Almost surely, 2^21251403311 is an apocalyptic number.

21251403311 is a deficient number, since it is larger than the sum of its proper divisors (925693393).

21251403311 is a wasteful number, since it uses less digits than its factorization.

21251403311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71661.

The product of its (nonzero) digits is 720, while the sum is 23.

Adding to 21251403311 its reverse (11330415212), we get a palindrome (32581818523).

The spelling of 21251403311 in words is "twenty-one billion, two hundred fifty-one million, four hundred three thousand, three hundred eleven".