21572021263 has 16 divisors (see below), whose sum is σ = 23293660320. Its totient is φ = 19859366016.

The previous prime is 21572021249. The next prime is 21572021267. The reversal of 21572021263 is 36212027512.

It is a cyclic number.

It is not a de Polignac number, because 21572021263 - 2⁵ = 21572021231 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 (21572021267) 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 15 ways as a sum of consecutive naturals, for example, 11491881 + ... + 11493757.

It is an arithmetic number, because the mean of its divisors is an integer number (1455853770).

Almost surely, 2^21572021263 is an apocalyptic number.

21572021263 is a deficient number, since it is larger than the sum of its proper divisors (1721639057).

21572021263 is a wasteful number, since it uses less digits than its factorization.

21572021263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3786.

The product of its (nonzero) digits is 10080, while the sum is 31.

Adding to 21572021263 its reverse (36212027512), we get a palindrome (57784048775).

The spelling of 21572021263 in words is "twenty-one billion, five hundred seventy-two million, twenty-one thousand, two hundred sixty-three".