21651267743 has 24 divisors (see below), whose sum is σ = 25736413824. Its totient is φ = 18156793200.

The previous prime is 21651267739. The next prime is 21651267751. The reversal of 21651267743 is 34776215612.

It is a happy number.

It is not a de Polignac number, because 21651267743 - 2² = 21651267739 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21651267694 and 21651267703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21651267713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 431996 + ... + 479502.

It is an arithmetic number, because the mean of its divisors is an integer number (1072350576).

Almost surely, 2^21651267743 is an apocalyptic number.

21651267743 is a deficient number, since it is larger than the sum of its proper divisors (4085146081).

21651267743 is a wasteful number, since it uses less digits than its factorization.

21651267743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47723 (or 47716 counting only the distinct ones).

The product of its digits is 423360, while the sum is 44.

The spelling of 21651267743 in words is "twenty-one billion, six hundred fifty-one million, two hundred sixty-seven thousand, seven hundred forty-three".