642157894801 has 2 divisors, whose sum is σ = 642157894802. Its totient is φ = 642157894800.

The previous prime is 642157894793. The next prime is 642157894883. The reversal of 642157894801 is 108498751246.

642157894801 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 324445299201 + 317712595600 = 569601^2 + 563660^2 .

It is a cyclic number.

It is not a de Polignac number, because 642157894801 - 2³ = 642157894793 is a prime.

It is not a weakly prime, because it can be changed into another prime (642157894891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321078947400 + 321078947401.

It is an arithmetic number, because the mean of its divisors is an integer number (321078947401).

Almost surely, 2^642157894801 is an apocalyptic number.

It is an amenable number.

642157894801 is a deficient number, since it is larger than the sum of its proper divisors (1).

642157894801 is an equidigital number, since it uses as much as digits as its factorization.

642157894801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 642157894801 in words is "six hundred forty-two billion, one hundred fifty-seven million, eight hundred ninety-four thousand, eight hundred one".