20276561655 has 64 divisors (see below), whose sum is σ = 41974225920. Its totient is φ = 9094370688.

The previous prime is 20276561647. The next prime is 20276561659. The reversal of 20276561655 is 55616567202.

20276561655 is a `hidden beast` number, since 2 + 0 + 27 + 6 + 5 + 616 + 5 + 5 = 666.

It is not a de Polignac number, because 20276561655 - 2³ = 20276561647 is a prime.

It is a super-2 number, since 2×20276561655² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 20276561655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20276561659) 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, 152337 + ... + 252506.

It is an arithmetic number, because the mean of its divisors is an integer number (655847280).

Almost surely, 2^20276561655 is an apocalyptic number.

20276561655 is an abundant number, since it is smaller than the sum of its proper divisors (21697664265).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20276561655 is a wasteful number, since it uses less digits than its factorization.

20276561655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404917 (or 404911 counting only the distinct ones).

The product of its (nonzero) digits is 756000, while the sum is 45.

The spelling of 20276561655 in words is "twenty billion, two hundred seventy-six million, five hundred sixty-one thousand, six hundred fifty-five".