21356253773356 has 24 divisors (see below), whose sum is σ = 37380688091264. Its totient is φ = 10676057420160.

The previous prime is 21356253773353. The next prime is 21356253773381. The reversal of 21356253773356 is 65337735265312.

It is a self number, because there is not a number n which added to its sum of digits gives 21356253773356.

It is not an unprimeable number, because it can be changed into a prime (21356253773353) 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, 576850126 + ... + 576887146.

Almost surely, 2^{21356253773356} is an apocalyptic number.

It is an amenable number.

21356253773356 is a deficient number, since it is larger than the sum of its proper divisors (16024434317908).

21356253773356 is a wasteful number, since it uses less digits than its factorization.

21356253773356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61081 (or 61079 counting only the distinct ones).

The product of its digits is 71442000, while the sum is 58.

The spelling of 21356253773356 in words is "twenty-one trillion, three hundred fifty-six billion, two hundred fifty-three million, seven hundred seventy-three thousand, three hundred fifty-six".