642863637 has 24 divisors (see below), whose sum is σ = 1003222584. Its totient is φ = 394337664.

The previous prime is 642863633. The next prime is 642863671. The reversal of 642863637 is 736368246.

642863637 is a `hidden beast` number, since 6 + 4 + 2 + 8 + 6 + 3 + 637 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 77898276 + 564965361 = 8826^2 + 23769^2 .

It is not a de Polignac number, because 642863637 - 2² = 642863633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 642863592 and 642863601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642863633) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28423 + ... + 45755.

It is an arithmetic number, because the mean of its divisors is an integer number (41800941).

Almost surely, 2^642863637 is an apocalyptic number.

It is an amenable number.

642863637 is a deficient number, since it is larger than the sum of its proper divisors (360358947).

642863637 is a wasteful number, since it uses less digits than its factorization.

642863637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17669 (or 17666 counting only the distinct ones).

The product of its digits is 870912, while the sum is 45.

The square root of 642863637 is about 25354.7557077563. The cubic root of 642863637 is about 863.0572801792.

The spelling of 642863637 in words is "six hundred forty-two million, eight hundred sixty-three thousand, six hundred thirty-seven".