21915218763 has 16 divisors (see below), whose sum is σ = 32924275200. Its totient is φ = 14404367880.

The previous prime is 21915218761. The next prime is 21915218783. The reversal of 21915218763 is 36781251912.

It is not a de Polignac number, because 21915218763 - 2¹ = 21915218761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21915218761) 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, 5714103 + ... + 5717936.

It is an arithmetic number, because the mean of its divisors is an integer number (2057767200).

Almost surely, 2^21915218763 is an apocalyptic number.

21915218763 is a deficient number, since it is larger than the sum of its proper divisors (11009056437).

21915218763 is a wasteful number, since it uses less digits than its factorization.

21915218763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11432119 (or 11432113 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The spelling of 21915218763 in words is "twenty-one billion, nine hundred fifteen million, two hundred eighteen thousand, seven hundred sixty-three".