642888853 has 2 divisors, whose sum is σ = 642888854. Its totient is φ = 642888852.

The previous prime is 642888823. The next prime is 642888877. The reversal of 642888853 is 358888246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 642774609 + 114244 = 25353^2 + 338^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642888853 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642888853.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642888823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321444426 + 321444427.

It is an arithmetic number, because the mean of its divisors is an integer number (321444427).

Almost surely, 2^642888853 is an apocalyptic number.

It is an amenable number.

642888853 is a deficient number, since it is larger than the sum of its proper divisors (1).

642888853 is an equidigital number, since it uses as much as digits as its factorization.

642888853 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2949120, while the sum is 52.

The square root of 642888853 is about 25355.2529665945. The cubic root of 642888853 is about 863.0685643596.

The spelling of 642888853 in words is "six hundred forty-two million, eight hundred eighty-eight thousand, eight hundred fifty-three".