21768105853 has 16 divisors (see below), whose sum is σ = 24205382656. Its totient is φ = 19440155520.

The previous prime is 21768105847. The next prime is 21768105859. The reversal of 21768105853 is 35850186712.

It is an interprime number because it is at equal distance from previous prime (21768105847) and next prime (21768105859).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21768105853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768105859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2803825 + ... + 2811577.

It is an arithmetic number, because the mean of its divisors is an integer number (1512836416).

Almost surely, 2^21768105853 is an apocalyptic number.

It is an amenable number.

21768105853 is a deficient number, since it is larger than the sum of its proper divisors (2437276803).

21768105853 is a wasteful number, since it uses less digits than its factorization.

21768105853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14764.

The product of its (nonzero) digits is 403200, while the sum is 46.

The spelling of 21768105853 in words is "twenty-one billion, seven hundred sixty-eight million, one hundred five thousand, eight hundred fifty-three".