21183747857 has 8 divisors (see below), whose sum is σ = 22205087520. Its totient is φ = 20186439840.

The previous prime is 21183747797. The next prime is 21183747863. The reversal of 21183747857 is 75874738112.

It is a happy number.

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 21183747857 - 2¹² = 21183743761 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21183747799 and 21183747808.

It is not an unprimeable number, because it can be changed into a prime (21183747887) 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, 6006107 + ... + 6009632.

It is an arithmetic number, because the mean of its divisors is an integer number (2775635940).

Almost surely, 2^21183747857 is an apocalyptic number.

It is an amenable number.

21183747857 is a deficient number, since it is larger than the sum of its proper divisors (1021339663).

21183747857 is a wasteful number, since it uses less digits than its factorization.

21183747857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12015823.

The product of its digits is 2634240, while the sum is 53.

The spelling of 21183747857 in words is "twenty-one billion, one hundred eighty-three million, seven hundred forty-seven thousand, eight hundred fifty-seven".