642617671 has 4 divisors (see below), whose sum is σ = 657562312. Its totient is φ = 627673032.

The previous prime is 642617611. The next prime is 642617683. The reversal of 642617671 is 176716246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 642617671 - 2⁹ = 642617159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642617611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7472256 + ... + 7472341.

It is an arithmetic number, because the mean of its divisors is an integer number (164390578).

Almost surely, 2^642617671 is an apocalyptic number.

642617671 is a deficient number, since it is larger than the sum of its proper divisors (14944641).

642617671 is a wasteful number, since it uses less digits than its factorization.

642617671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14944640.

The product of its digits is 84672, while the sum is 40.

The square root of 642617671 is about 25349.9047532727. The cubic root of 642617671 is about 862.9471947145.

The spelling of 642617671 in words is "six hundred forty-two million, six hundred seventeen thousand, six hundred seventy-one".