21756263843 has 8 divisors (see below), whose sum is σ = 22245347040. Its totient is φ = 21271452480.

The previous prime is 21756263833. The next prime is 21756263873. The reversal of 21756263843 is 34836265712.

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 21756263843 - 2⁴ = 21756263827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21756263833) 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, 1057658 + ... + 1078031.

It is an arithmetic number, because the mean of its divisors is an integer number (2780668380).

Almost surely, 2^21756263843 is an apocalyptic number.

21756263843 is a deficient number, since it is larger than the sum of its proper divisors (489083197).

21756263843 is a wasteful number, since it uses less digits than its factorization.

21756263843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135917.

The product of its digits is 1451520, while the sum is 47.

The spelling of 21756263843 in words is "twenty-one billion, seven hundred fifty-six million, two hundred sixty-three thousand, eight hundred forty-three".