21418905465 has 16 divisors (see below), whose sum is σ = 38078054400. Its totient is φ = 11423416176.

The previous prime is 21418905461. The next prime is 21418905467. The reversal of 21418905465 is 56450981412.

21418905465 is a `hidden beast` number, since 2 + 1 + 4 + 18 + 90 + 546 + 5 = 666.

It is not a de Polignac number, because 21418905465 - 2² = 21418905461 is a prime.

It is a super-2 number, since 2×21418905465² (a number of 21 digits) contains 22 as substring.

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 21418905465.

It is not an unprimeable number, because it can be changed into a prime (21418905461) 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, 79329145 + ... + 79329414.

It is an arithmetic number, because the mean of its divisors is an integer number (2379878400).

Almost surely, 2^21418905465 is an apocalyptic number.

It is an amenable number.

21418905465 is a deficient number, since it is larger than the sum of its proper divisors (16659148935).

21418905465 is a wasteful number, since it uses less digits than its factorization.

21418905465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158658573 (or 158658567 counting only the distinct ones).

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

The spelling of 21418905465 in words is "twenty-one billion, four hundred eighteen million, nine hundred five thousand, four hundred sixty-five".