642088594891 has 2 divisors, whose sum is σ = 642088594892. Its totient is φ = 642088594890.

The previous prime is 642088594853. The next prime is 642088594969. The reversal of 642088594891 is 198495880246.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642088594891 is a prime.

It is a super-2 number, since 2×642088594891² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (642088594991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321044297445 + 321044297446.

It is an arithmetic number, because the mean of its divisors is an integer number (321044297446).

Almost surely, 2^642088594891 is an apocalyptic number.

642088594891 is a deficient number, since it is larger than the sum of its proper divisors (1).

642088594891 is an equidigital number, since it uses as much as digits as its factorization.

642088594891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39813120, while the sum is 64.

The spelling of 642088594891 in words is "six hundred forty-two billion, eighty-eight million, five hundred ninety-four thousand, eight hundred ninety-one".