642997917611 has 16 divisors (see below), whose sum is σ = 736918828800. Its totient is φ = 549593404128.

The previous prime is 642997917581. The next prime is 642997917619. The reversal of 642997917611 is 116719799246.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642997917611 is a prime.

It is a super-3 number, since 3×642997917611³ (a number of 36 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (62) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (642997917619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39833180 + ... + 39849318.

It is an arithmetic number, because the mean of its divisors is an integer number (46057426800).

Almost surely, 2^642997917611 is an apocalyptic number.

642997917611 is a deficient number, since it is larger than the sum of its proper divisors (93920911189).

642997917611 is a wasteful number, since it uses less digits than its factorization.

642997917611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31778.

The product of its digits is 10287648, while the sum is 62.

The spelling of 642997917611 in words is "six hundred forty-two billion, nine hundred ninety-seven million, nine hundred seventeen thousand, six hundred eleven".