20563512261 has 16 divisors (see below), whose sum is σ = 28908200640. Its totient is φ = 12966272640.

The previous prime is 20563512259. The next prime is 20563512283. The reversal of 20563512261 is 16221536502.

It is not a de Polignac number, because 20563512261 - 2¹ = 20563512259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20563512251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259320 + ... + 329201.

It is an arithmetic number, because the mean of its divisors is an integer number (1806762540).

Almost surely, 2^20563512261 is an apocalyptic number.

It is an amenable number.

20563512261 is a deficient number, since it is larger than the sum of its proper divisors (8344688379).

20563512261 is a wasteful number, since it uses less digits than its factorization.

20563512261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589156.

The product of its (nonzero) digits is 21600, while the sum is 33.

The spelling of 20563512261 in words is "twenty billion, five hundred sixty-three million, five hundred twelve thousand, two hundred sixty-one".