21300023643 has 16 divisors (see below), whose sum is σ = 28861837056. Its totient is φ = 13969971680.

The previous prime is 21300023621. The next prime is 21300023651. The reversal of 21300023643 is 34632000312.

It is a cyclic number.

It is not a de Polignac number, because 21300023643 - 2¹² = 21300019547 is a prime.

21300023643 is a modest number, since divided by 23643 gives 21300 as remainder.

It is not an unprimeable number, because it can be changed into a prime (21300023543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7596 + ... + 206537.

It is an arithmetic number, because the mean of its divisors is an integer number (1803864816).

Almost surely, 2^21300023643 is an apocalyptic number.

21300023643 is a deficient number, since it is larger than the sum of its proper divisors (7561813413).

21300023643 is a wasteful number, since it uses less digits than its factorization.

21300023643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214674.

The product of its (nonzero) digits is 2592, while the sum is 24.

Adding to 21300023643 its reverse (34632000312), we get a palindrome (55932023955).

The spelling of 21300023643 in words is "twenty-one billion, three hundred million, twenty-three thousand, six hundred forty-three".