20405259405 has 12 divisors (see below), whose sum is σ = 35369116380. Its totient is φ = 10882804992.

The previous prime is 20405259379. The next prime is 20405259419. The reversal of 20405259405 is 50495250402.

20405259405 is a `hidden beast` number, since 2 + 0 + 40 + 525 + 94 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9419284809 + 10985974596 = 97053^2 + 104814^2 .

It is not a de Polignac number, because 20405259405 - 2¹¹ = 20405257357 is a prime.

It is a super-2 number, since 2×20405259405² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20405259405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 226725060 + ... + 226725149.

It is an arithmetic number, because the mean of its divisors is an integer number (2947426365).

Almost surely, 2^20405259405 is an apocalyptic number.

It is an amenable number.

20405259405 is a deficient number, since it is larger than the sum of its proper divisors (14963856975).

20405259405 is a wasteful number, since it uses less digits than its factorization.

20405259405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453450220 (or 453450217 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 20405259405 in words is "twenty billion, four hundred five million, two hundred fifty-nine thousand, four hundred five".