642021642 has 24 divisors (see below), whose sum is σ = 1392362244. Its totient is φ = 213804864.

The previous prime is 642021631. The next prime is 642021673. The reversal of 642021642 is 246120246.

642021642 is a `hidden beast` number, since 642 + 0 + 2 + 16 + 4 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 529046001 + 112975641 = 23001^2 + 10629^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3358 + ... + 35990.

Almost surely, 2^642021642 is an apocalyptic number.

642021642 is an abundant number, since it is smaller than the sum of its proper divisors (750340602).

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

642021642 is a wasteful number, since it uses less digits than its factorization.

642021642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33734 (or 33731 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 642021642 is about 25338.1459858451. The cubic root of 642021642 is about 862.6803171831.

Adding to 642021642 its reverse (246120246), we get a palindrome (888141888).

The spelling of 642021642 in words is "six hundred forty-two million, twenty-one thousand, six hundred forty-two".