21168830565 has 48 divisors (see below), whose sum is σ = 37447003776. Its totient is φ = 11059804800.

The previous prime is 21168830561. The next prime is 21168830569. The reversal of 21168830565 is 56503886112.

21168830565 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 8 + 83 + 0 + 565 = 666.

It is an interprime number because it is at equal distance from previous prime (21168830561) and next prime (21168830569).

It is not a de Polignac number, because 21168830565 - 2² = 21168830561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21168830565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21168830561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 526320 + ... + 565110.

It is an arithmetic number, because the mean of its divisors is an integer number (780145912).

Almost surely, 2^21168830565 is an apocalyptic number.

It is an amenable number.

21168830565 is a deficient number, since it is larger than the sum of its proper divisors (16278173211).

21168830565 is a wasteful number, since it uses less digits than its factorization.

21168830565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39050 (or 39047 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 21168830565 in words is "twenty-one billion, one hundred sixty-eight million, eight hundred thirty thousand, five hundred sixty-five".