21749857148 has 6 divisors (see below), whose sum is σ = 38062250016. Its totient is φ = 10874928572.

The previous prime is 21749857123. The next prime is 21749857159. The reversal of 21749857148 is 84175894712.

It is a junction number, because it is equal to n+sod(n) for n = 21749857093 and 21749857102.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2718732140 + ... + 2718732147.

It is an arithmetic number, because the mean of its divisors is an integer number (6343708336).

Almost surely, 2^21749857148 is an apocalyptic number.

It is an amenable number.

21749857148 is a deficient number, since it is larger than the sum of its proper divisors (16312392868).

21749857148 is a wasteful number, since it uses less digits than its factorization.

21749857148 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5437464291 (or 5437464289 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 56.

The spelling of 21749857148 in words is "twenty-one billion, seven hundred forty-nine million, eight hundred fifty-seven thousand, one hundred forty-eight".