642915438 has 32 divisors (see below), whose sum is σ = 1407722112. Its totient is φ = 194128800.

The previous prime is 642915353. The next prime is 642915443. The reversal of 642915438 is 834519246.

It is a self number, because there is not a number n which added to its sum of digits gives 642915438.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1468 + ... + 35888.

It is an arithmetic number, because the mean of its divisors is an integer number (43991316).

Almost surely, 2^642915438 is an apocalyptic number.

642915438 is an abundant number, since it is smaller than the sum of its proper divisors (764806674).

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

642915438 is a wasteful number, since it uses less digits than its factorization.

642915438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34720.

The product of its digits is 207360, while the sum is 42.

The square root of 642915438 is about 25355.7772115153. Note that the first 3 decimals coincide. The cubic root of 642915438 is about 863.0804608491.

The spelling of 642915438 in words is "six hundred forty-two million, nine hundred fifteen thousand, four hundred thirty-eight".