642726 has 24 divisors (see below), whose sum is σ = 1591824. Its totient is φ = 183600.

The previous prime is 642701. The next prime is 642737. The reversal of 642726 is 627246.

It is a super-2 number, since 2×642726² = 826193422152, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642726.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 2425 + ... + 2676.

It is an arithmetic number, because the mean of its divisors is an integer number (66326).

2⁶⁴²⁷²⁶ is an apocalyptic number.

642726 is an abundant number, since it is smaller than the sum of its proper divisors (949098).

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

642726 is a wasteful number, since it uses less digits than its factorization.

642726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5116 (or 5113 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 642726 is about 801.7019396259. The cubic root of 642726 is about 86.2995682309.

The spelling of 642726 in words is "six hundred forty-two thousand, seven hundred twenty-six".