21153712833 has 72 divisors (see below), whose sum is σ = 37433541600. Its totient is φ = 11431031040.

The previous prime is 21153712829. The next prime is 21153712847. The reversal of 21153712833 is 33821735112.

It is a happy number.

21153712833 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 371 + 283 + 3 = 666.

It is not a de Polignac number, because 21153712833 - 2² = 21153712829 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21153712033) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 321678 + ... + 381816.

It is an arithmetic number, because the mean of its divisors is an integer number (519910300).

Almost surely, 2^21153712833 is an apocalyptic number.

It is an amenable number.

21153712833 is a deficient number, since it is larger than the sum of its proper divisors (16279828767).

21153712833 is a wasteful number, since it uses less digits than its factorization.

21153712833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60203 (or 60189 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The spelling of 21153712833 in words is "twenty-one billion, one hundred fifty-three million, seven hundred twelve thousand, eight hundred thirty-three".