21947751727 has 8 divisors (see below), whose sum is σ = 24452428032. Its totient is φ = 19527979800.

The previous prime is 21947751701. The next prime is 21947751731. The reversal of 21947751727 is 72715774912.

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-21947751727 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 (21947751227) 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, 21225549 + ... + 21226582.

It is an arithmetic number, because the mean of its divisors is an integer number (3056553504).

Almost surely, 2^21947751727 is an apocalyptic number.

21947751727 is a deficient number, since it is larger than the sum of its proper divisors (2504676305).

21947751727 is a wasteful number, since it uses less digits than its factorization.

21947751727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42452189.

The product of its digits is 1728720, while the sum is 52.

The spelling of 21947751727 in words is "twenty-one billion, nine hundred forty-seven million, seven hundred fifty-one thousand, seven hundred twenty-seven".