21386749999 has 16 divisors (see below), whose sum is σ = 22892126080. Its totient is φ = 19919662560.

The previous prime is 21386749981. The next prime is 21386750003. The reversal of 21386749999 is 99994768312.

It is a cyclic number.

It is not a de Polignac number, because 21386749999 - 2⁹ = 21386749487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21386746999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4525852 + ... + 4530574.

It is an arithmetic number, because the mean of its divisors is an integer number (1430757880).

Almost surely, 2^21386749999 is an apocalyptic number.

21386749999 is a deficient number, since it is larger than the sum of its proper divisors (1505376081).

21386749999 is a wasteful number, since it uses less digits than its factorization.

21386749999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8710.

The product of its digits is 52907904, while the sum is 67.

The spelling of 21386749999 in words is "twenty-one billion, three hundred eighty-six million, seven hundred forty-nine thousand, nine hundred ninety-nine".