642871242 has 160 divisors (see below), whose sum is σ = 1645754880. Its totient is φ = 186157440.

The previous prime is 642871241. The next prime is 642871259. The reversal of 642871242 is 242178246.

642871242 is a `hidden beast` number, since 642 + 8 + 7 + 1 + 2 + 4 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 642871197 and 642871206.

It is not an unprimeable number, because it can be changed into a prime (642871241) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2807184 + ... + 2807412.

It is an arithmetic number, because the mean of its divisors is an integer number (10285968).

Almost surely, 2^642871242 is an apocalyptic number.

642871242 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 642871242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822877440).

642871242 is an abundant number, since it is smaller than the sum of its proper divisors (1002883638).

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

642871242 is a wasteful number, since it uses less digits than its factorization.

642871242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330 (or 321 counting only the distinct ones).

The product of its digits is 43008, while the sum is 36.

The square root of 642871242 is about 25354.9056791777. The cubic root of 642871242 is about 863.0606834539.

The spelling of 642871242 in words is "six hundred forty-two million, eight hundred seventy-one thousand, two hundred forty-two".