642487869 has 48 divisors (see below), whose sum is σ = 1040719680. Its totient is φ = 394709760.

The previous prime is 642487849. The next prime is 642487877. The reversal of 642487869 is 968784246.

It is not a de Polignac number, because 642487869 - 2¹⁵ = 642455101 is a prime.

It is a super-2 number, since 2×642487869² = 825581323624322322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642487849) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 168949 + ... + 172709.

It is an arithmetic number, because the mean of its divisors is an integer number (21681660).

Almost surely, 2^642487869 is an apocalyptic number.

It is an amenable number.

642487869 is a deficient number, since it is larger than the sum of its proper divisors (398231811).

642487869 is a wasteful number, since it uses less digits than its factorization.

642487869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3832 (or 3820 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The square root of 642487869 is about 25347.3444171179. The cubic root of 642487869 is about 862.8890887211.

The spelling of 642487869 in words is "six hundred forty-two million, four hundred eighty-seven thousand, eight hundred sixty-nine".