21064742399 has 8 divisors (see below), whose sum is σ = 21211604592. Its totient is φ = 20918269440.

The previous prime is 21064742359. The next prime is 21064742429. The reversal of 21064742399 is 99324746012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21064742399 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 (21064742339) 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, 11729 + ... + 205589.

It is an arithmetic number, because the mean of its divisors is an integer number (2651450574).

Almost surely, 2^21064742399 is an apocalyptic number.

21064742399 is a deficient number, since it is larger than the sum of its proper divisors (146862193).

21064742399 is a wasteful number, since it uses less digits than its factorization.

21064742399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194617.

The product of its (nonzero) digits is 653184, while the sum is 47.

The spelling of 21064742399 in words is "twenty-one billion, sixty-four million, seven hundred forty-two thousand, three hundred ninety-nine".