21541844863 has 12 divisors (see below), whose sum is σ = 27336961512. Its totient is φ = 16785852720.

The previous prime is 21541844843. The next prime is 21541844867. The reversal of 21541844863 is 36844814512.

It is not a de Polignac number, because 21541844863 - 2²⁵ = 21508290431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541844867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19982620 + ... + 19983697.

It is an arithmetic number, because the mean of its divisors is an integer number (2278080126).

Almost surely, 2^21541844863 is an apocalyptic number.

21541844863 is a deficient number, since it is larger than the sum of its proper divisors (5795116649).

21541844863 is a wasteful number, since it uses less digits than its factorization.

21541844863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39966342 (or 39966335 counting only the distinct ones).

The product of its digits is 737280, while the sum is 46.

It can be divided in two parts, 215418 and 44863, that added together give a triangular number (260281 = T₇₂₁).

The spelling of 21541844863 in words is "twenty-one billion, five hundred forty-one million, eight hundred forty-four thousand, eight hundred sixty-three".