21803816265 has 32 divisors (see below), whose sum is σ = 43494368256. Its totient is φ = 9061325760.

The previous prime is 21803816249. The next prime is 21803816297. The reversal of 21803816265 is 56261830812.

It is not a de Polignac number, because 21803816265 - 2⁴ = 21803816249 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9437727 + ... + 9440036.

It is an arithmetic number, because the mean of its divisors is an integer number (1359199008).

Almost surely, 2^21803816265 is an apocalyptic number.

It is an amenable number.

21803816265 is a deficient number, since it is larger than the sum of its proper divisors (21690551991).

21803816265 is a wasteful number, since it uses less digits than its factorization.

21803816265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18877789.

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 21803816265 in words is "twenty-one billion, eight hundred three million, eight hundred sixteen thousand, two hundred sixty-five".