20645824505511 has 16 divisors (see below), whose sum is σ = 27915757850880. Its totient is φ = 13569890927040.

The previous prime is 20645824505507. The next prime is 20645824505533. The reversal of 20645824505511 is 11550542854602.

It is not a de Polignac number, because 20645824505511 - 2² = 20645824505507 is a prime.

It is a super-2 number, since 2×20645824505511² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645824505611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23959380 + ... + 24806118.

It is an arithmetic number, because the mean of its divisors is an integer number (1744734865680).

Almost surely, 2^{20645824505511} is an apocalyptic number.

20645824505511 is a deficient number, since it is larger than the sum of its proper divisors (7269933345369).

20645824505511 is a wasteful number, since it uses less digits than its factorization.

20645824505511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961286.

The product of its (nonzero) digits is 1920000, while the sum is 48.

The spelling of 20645824505511 in words is "twenty trillion, six hundred forty-five billion, eight hundred twenty-four million, five hundred five thousand, five hundred eleven".