642738 has 8 divisors (see below), whose sum is σ = 1285488. Its totient is φ = 214244.

The previous prime is 642737. The next prime is 642739. The reversal of 642738 is 837246.

It is an interprime number because it is at equal distance from previous prime (642737) and next prime (642739).

It is a sphenic number, since it is the product of 3 distinct primes.

642738 is an admirable number.

It is a super-2 number, since 2×642738² = 826224273288, which contains 22 as substring.

It is a d-powerful number, because it can be written as 6 + 4⁴ + 7⁶ + 2¹⁹ + 3³ + 8³ .

It is not an unprimeable number, because it can be changed into a prime (642737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53556 + ... + 53567.

It is an arithmetic number, because the mean of its divisors is an integer number (160686).

2⁶⁴²⁷³⁸ is an apocalyptic number.

642738 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

642738 is a wasteful number, since it uses less digits than its factorization.

642738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107128.

The product of its digits is 8064, while the sum is 30.

The square root of 642738 is about 801.7094236692. The cubic root of 642738 is about 86.3001053122.

The spelling of 642738 in words is "six hundred forty-two thousand, seven hundred thirty-eight".