21817057738 has 8 divisors (see below), whose sum is σ = 37400670432. Its totient is φ = 9350167596.

The previous prime is 21817057727. The next prime is 21817057741. The reversal of 21817057738 is 83775071812.

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

It is a junction number, because it is equal to n+sod(n) for n = 21817057691 and 21817057700.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 779180620 + ... + 779180647.

It is an arithmetic number, because the mean of its divisors is an integer number (4675083804).

Almost surely, 2^21817057738 is an apocalyptic number.

21817057738 is a deficient number, since it is larger than the sum of its proper divisors (15583612694).

21817057738 is a wasteful number, since it uses less digits than its factorization.

21817057738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1558361276.

The product of its (nonzero) digits is 658560, while the sum is 49.

The spelling of 21817057738 in words is "twenty-one billion, eight hundred seventeen million, fifty-seven thousand, seven hundred thirty-eight".