20766557655 has 192 divisors, whose sum is σ = 42037107840. Its totient is φ = 9782083584.

The previous prime is 20766557611. The next prime is 20766557659. The reversal of 20766557655 is 55675566702.

It is a happy number.

20766557655 is a `hidden beast` number, since 2 + 0 + 7 + 6 + 65 + 576 + 5 + 5 = 666.

It is not a de Polignac number, because 20766557655 - 2¹⁹ = 20766033367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20766557659) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 22162347 + ... + 22163283.

It is an arithmetic number, because the mean of its divisors is an integer number (218943270).

Almost surely, 2^20766557655 is an apocalyptic number.

20766557655 is an abundant number, since it is smaller than the sum of its proper divisors (21270550185).

20766557655 is a wasteful number, since it uses less digits than its factorization.

20766557655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 13230000, while the sum is 54.

The spelling of 20766557655 in words is "twenty billion, seven hundred sixty-six million, five hundred fifty-seven thousand, six hundred fifty-five".