6651564555651 has 16 divisors (see below), whose sum is σ = 8870941390080. Its totient is φ = 4433282215200.

The previous prime is 6651564555631. The next prime is 6651564555673. The reversal of 6651564555651 is 1565554651566.

It is not a de Polignac number, because 6651564555651 - 2¹⁹ = 6651564031363 is a prime.

It is a super-2 number, since 2×6651564555651² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6651564555631) 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, 299757465 + ... + 299779653.

It is an arithmetic number, because the mean of its divisors is an integer number (554433836880).

Almost surely, 2^{6651564555651} is an apocalyptic number.

6651564555651 is a deficient number, since it is larger than the sum of its proper divisors (2219376834429).

6651564555651 is a wasteful number, since it uses less digits than its factorization.

6651564555651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42346.

The product of its digits is 81000000, while the sum is 60.

The spelling of 6651564555651 in words is "six trillion, six hundred fifty-one billion, five hundred sixty-four million, five hundred fifty-five thousand, six hundred fifty-one".