21717774247 has 8 divisors (see below), whose sum is σ = 23481556560. Its totient is φ = 19967304000.

The previous prime is 21717774187. The next prime is 21717774341. The reversal of 21717774247 is 74247771712.

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

It is a cyclic number.

It is not a de Polignac number, because 21717774247 - 2¹⁹ = 21717249959 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21717774247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21717774847) 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, 3324622 + ... + 3331147.

It is an arithmetic number, because the mean of its divisors is an integer number (2935194570).

Almost surely, 2^21717774247 is an apocalyptic number.

21717774247 is a deficient number, since it is larger than the sum of its proper divisors (1763782313).

21717774247 is a wasteful number, since it uses less digits than its factorization.

21717774247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6656033.

The product of its digits is 1075648, while the sum is 49.

The spelling of 21717774247 in words is "twenty-one billion, seven hundred seventeen million, seven hundred seventy-four thousand, two hundred forty-seven".