20265640405 has 32 divisors (see below), whose sum is σ = 24998035968. Its totient is φ = 15767136000.

The previous prime is 20265640403. The next prime is 20265640427. The reversal of 20265640405 is 50404656202.

It is not a de Polignac number, because 20265640405 - 2¹ = 20265640403 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20265640403) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11365144 + ... + 11366926.

It is an arithmetic number, because the mean of its divisors is an integer number (781188624).

Almost surely, 2^20265640405 is an apocalyptic number.

It is an amenable number.

20265640405 is a deficient number, since it is larger than the sum of its proper divisors (4732395563).

20265640405 is a wasteful number, since it uses less digits than its factorization.

20265640405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2277.

The product of its (nonzero) digits is 57600, while the sum is 34.

The spelling of 20265640405 in words is "twenty billion, two hundred sixty-five million, six hundred forty thousand, four hundred five".