642249805 has 16 divisors (see below), whose sum is σ = 805034880. Its totient is φ = 491254848.

The previous prime is 642249793. The next prime is 642249841. The reversal of 642249805 is 508942246.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642249805 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6567 + ... + 36436.

It is an arithmetic number, because the mean of its divisors is an integer number (50314680).

Almost surely, 2^642249805 is an apocalyptic number.

It is an amenable number.

642249805 is a deficient number, since it is larger than the sum of its proper divisors (162785075).

642249805 is a wasteful number, since it uses less digits than its factorization.

642249805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43140.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 642249805 is about 25342.6479476790. The cubic root of 642249805 is about 862.7824987941.

The spelling of 642249805 in words is "six hundred forty-two million, two hundred forty-nine thousand, eight hundred five".