21723631777 has 8 divisors (see below), whose sum is σ = 22425552864. Its totient is φ = 21030652608.

The previous prime is 21723631759. The next prime is 21723631801. The reversal of 21723631777 is 77713632712.

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-21723631777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21723631177) 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, 2230543 + ... + 2240260.

It is an arithmetic number, because the mean of its divisors is an integer number (2803194108).

Almost surely, 2^21723631777 is an apocalyptic number.

It is an amenable number.

21723631777 is a deficient number, since it is larger than the sum of its proper divisors (701921087).

21723631777 is a wasteful number, since it uses less digits than its factorization.

21723631777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4470959.

The product of its digits is 518616, while the sum is 46.

The spelling of 21723631777 in words is "twenty-one billion, seven hundred twenty-three million, six hundred thirty-one thousand, seven hundred seventy-seven".