21143563261 has 8 divisors (see below), whose sum is σ = 22633610400. Its totient is φ = 19691238960.

The previous prime is 21143563247. The next prime is 21143563307. The reversal of 21143563261 is 16236534112.

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 21143563261 - 2⁵ = 21143563229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143564261) by changing a digit.

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, 9429550 + ... + 9431791.

It is an arithmetic number, because the mean of its divisors is an integer number (2829201300).

Almost surely, 2^21143563261 is an apocalyptic number.

It is an amenable number.

21143563261 is a deficient number, since it is larger than the sum of its proper divisors (1490047139).

21143563261 is a wasteful number, since it uses less digits than its factorization.

21143563261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18861419.

The product of its digits is 25920, while the sum is 34.

The spelling of 21143563261 in words is "twenty-one billion, one hundred forty-three million, five hundred sixty-three thousand, two hundred sixty-one".