21905785743 has 32 divisors (see below), whose sum is σ = 29718475776. Its totient is φ = 14351328768.

The previous prime is 21905785697. The next prime is 21905785751. The reversal of 21905785743 is 34758750912.

It is not a de Polignac number, because 21905785743 - 2⁶ = 21905785679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21905781743) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24696046 + ... + 24696932.

It is an arithmetic number, because the mean of its divisors is an integer number (928702368).

Almost surely, 2^21905785743 is an apocalyptic number.

21905785743 is a deficient number, since it is larger than the sum of its proper divisors (7812690033).

21905785743 is a wasteful number, since it uses less digits than its factorization.

21905785743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543.

The product of its (nonzero) digits is 2116800, while the sum is 51.

The spelling of 21905785743 in words is "twenty-one billion, nine hundred five million, seven hundred eighty-five thousand, seven hundred forty-three".