21818499345 has 24 divisors (see below), whose sum is σ = 38153420136. Its totient is φ = 11533552128.

The previous prime is 21818499259. The next prime is 21818499379. The reversal of 21818499345 is 54399481812.

It is a happy number.

21818499345 is a `hidden beast` number, since 218 + 1 + 84 + 9 + 9 + 345 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 282643344 + 21535856001 = 16812^2 + 146751^2 .

It is not a de Polignac number, because 21818499345 - 2¹⁵ = 21818466577 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21818499291 and 21818499300.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2140294 + ... + 2150463.

It is an arithmetic number, because the mean of its divisors is an integer number (1589725839).

Almost surely, 2^21818499345 is an apocalyptic number.

It is an amenable number.

21818499345 is a deficient number, since it is larger than the sum of its proper divisors (16334920791).

21818499345 is a wasteful number, since it uses less digits than its factorization.

21818499345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4290881 (or 4290878 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 54.

The spelling of 21818499345 in words is "twenty-one billion, eight hundred eighteen million, four hundred ninety-nine thousand, three hundred forty-five".