20561561762 has 16 divisors (see below), whose sum is σ = 35279806272. Its totient is φ = 8804244240.

The previous prime is 20561561749. The next prime is 20561561767. The reversal of 20561561762 is 26716516502.

It is not an unprimeable number, because it can be changed into a prime (20561561767) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 638189 + ... + 669632.

It is an arithmetic number, because the mean of its divisors is an integer number (2204987892).

Almost surely, 2^20561561762 is an apocalyptic number.

20561561762 is a deficient number, since it is larger than the sum of its proper divisors (14718244510).

20561561762 is a wasteful number, since it uses less digits than its factorization.

20561561762 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1308953.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 20561561762 in words is "twenty billion, five hundred sixty-one million, five hundred sixty-one thousand, seven hundred sixty-two".