20265561099 has 64 divisors (see below), whose sum is σ = 34642094080. Its totient is φ = 11469444480.

The previous prime is 20265561091. The next prime is 20265561223. The reversal of 20265561099 is 99016556202.

It is a happy number.

20265561099 is a `hidden beast` number, since 2 + 0 + 2 + 6 + 556 + 1 + 0 + 99 = 666.

It is not a de Polignac number, because 20265561099 - 2³ = 20265561091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20265561091) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11067114 + ... + 11068944.

It is an arithmetic number, because the mean of its divisors is an integer number (541282720).

Almost surely, 2^20265561099 is an apocalyptic number.

20265561099 is a deficient number, since it is larger than the sum of its proper divisors (14376532981).

20265561099 is a wasteful number, since it uses less digits than its factorization.

20265561099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2377 (or 2371 counting only the distinct ones).

The product of its (nonzero) digits is 291600, while the sum is 45.

The spelling of 20265561099 in words is "twenty billion, two hundred sixty-five million, five hundred sixty-one thousand, ninety-nine".