21136218286545 has 24 divisors (see below), whose sum is σ = 36673610351976. Its totient is φ = 11261111705088.

The previous prime is 21136218286507. The next prime is 21136218286553. The reversal of 21136218286545 is 54568281263112.

21136218286545 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 6 + 2 + 18 + 2 + 86 + 545 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1513940758929 + 19622277527616 = 1230423^2 + 4429704^2 .

It is not a de Polignac number, because 21136218286545 - 2¹¹ = 21136218284497 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21136218286491 and 21136218286500.

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, 240331542 + ... + 240419471.

It is an arithmetic number, because the mean of its divisors is an integer number (1528067097999).

Almost surely, 2^{21136218286545} is an apocalyptic number.

It is an amenable number.

21136218286545 is a deficient number, since it is larger than the sum of its proper divisors (15537392065431).

21136218286545 is a wasteful number, since it uses less digits than its factorization.

21136218286545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480752001 (or 480751998 counting only the distinct ones).

The product of its digits is 5529600, while the sum is 54.

The spelling of 21136218286545 in words is "twenty-one trillion, one hundred thirty-six billion, two hundred eighteen million, two hundred eighty-six thousand, five hundred forty-five".