21445018769 has 16 divisors (see below), whose sum is σ = 22488516096. Its totient is φ = 20424096000.

The previous prime is 21445018759. The next prime is 21445018789. The reversal of 21445018769 is 96781054412.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21445018769 - 2⁴ = 21445018753 is a prime.

It is a super-2 number, since 2×21445018769² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21445018729) 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, 2490179 + ... + 2498775.

It is an arithmetic number, because the mean of its divisors is an integer number (1405532256).

Almost surely, 2^21445018769 is an apocalyptic number.

It is an amenable number.

21445018769 is a deficient number, since it is larger than the sum of its proper divisors (1043497327).

21445018769 is a wasteful number, since it uses less digits than its factorization.

21445018769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9896.

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 21445018769 in words is "twenty-one billion, four hundred forty-five million, eighteen thousand, seven hundred sixty-nine".