642635656065 has 128 divisors (see below), whose sum is σ = 1264432404480. Its totient is φ = 307620550656.

The previous prime is 642635656063. The next prime is 642635656097. The reversal of 642635656065 is 560656536246.

642635656065 is a `hidden beast` number, since 6 + 4 + 26 + 3 + 5 + 6 + 5 + 606 + 5 = 666.

It is not a de Polignac number, because 642635656065 - 2¹ = 642635656063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642635656063) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 154738029 + ... + 154742181.

It is an arithmetic number, because the mean of its divisors is an integer number (9878378160).

Almost surely, 2^642635656065 is an apocalyptic number.

642635656065 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

642635656065 is a deficient number, since it is larger than the sum of its proper divisors (621796748415).

642635656065 is a wasteful number, since it uses less digits than its factorization.

642635656065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6600 (or 6594 counting only the distinct ones).

The product of its (nonzero) digits is 23328000, while the sum is 54.

The spelling of 642635656065 in words is "six hundred forty-two billion, six hundred thirty-five million, six hundred fifty-six thousand, sixty-five".