642657869 has 8 divisors (see below), whose sum is σ = 758158848. Its totient is φ = 533080080.

The previous prime is 642657853. The next prime is 642657901. The reversal of 642657869 is 968756246.

642657869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642657869 - 2⁴ = 642657853 is a prime.

It is a super-2 number, since 2×642657869² = 826018273175242322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642657869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642657469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1480562 + ... + 1480995.

It is an arithmetic number, because the mean of its divisors is an integer number (94769856).

Almost surely, 2^642657869 is an apocalyptic number.

It is an amenable number.

642657869 is a deficient number, since it is larger than the sum of its proper divisors (115500979).

642657869 is a wasteful number, since it uses less digits than its factorization.

642657869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2961595.

The product of its digits is 4354560, while the sum is 53.

The square root of 642657869 is about 25350.6976038136. The cubic root of 642657869 is about 862.9651878021.

The spelling of 642657869 in words is "six hundred forty-two million, six hundred fifty-seven thousand, eight hundred sixty-nine".