642105646 has 96 divisors (see below), whose sum is σ = 1298082240. Its totient is φ = 231662592.

The previous prime is 642105643. The next prime is 642105649. The reversal of 642105646 is 646501246.

It is an interprime number because it is at equal distance from previous prime (642105643) and next prime (642105649).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642105641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1905190 + ... + 1905526.

It is an arithmetic number, because the mean of its divisors is an integer number (13521690).

Almost surely, 2^642105646 is an apocalyptic number.

642105646 is an abundant number, since it is smaller than the sum of its proper divisors (655976594).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642105646 is a wasteful number, since it uses less digits than its factorization.

642105646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 642105646 is about 25339.8035903990. The cubic root of 642105646 is about 862.7179407522.

The spelling of 642105646 in words is "six hundred forty-two million, one hundred five thousand, six hundred forty-six".