21768825933 has 6 divisors (see below), whose sum is σ = 31443859694. Its totient is φ = 14512550616.

The previous prime is 21768825929. The next prime is 21768825937. The reversal of 21768825933 is 33952886712.

It is an interprime number because it is at equal distance from previous prime (21768825929) and next prime (21768825937).

It can be written as a sum of positive squares in only one way, i.e., 15432347529 + 6336478404 = 124227^2 + 79602^2 .

It is not a de Polignac number, because 21768825933 - 2² = 21768825929 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 21768825933.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768825937) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1209379210 + ... + 1209379227.

Almost surely, 2^21768825933 is an apocalyptic number.

It is an amenable number.

21768825933 is a deficient number, since it is larger than the sum of its proper divisors (9675033761).

21768825933 is a wasteful number, since it uses less digits than its factorization.

21768825933 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2418758443 (or 2418758440 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The spelling of 21768825933 in words is "twenty-one billion, seven hundred sixty-eight million, eight hundred twenty-five thousand, nine hundred thirty-three".