742639 has 4 divisors (see below), whose sum is σ = 748440. Its totient is φ = 736840.

The previous prime is 742619. The next prime is 742657. The reversal of 742639 is 936247.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936247 = 13 ⋅72019.

It is a cyclic number.

It is not a de Polignac number, because 742639 - 2⁵ = 742607 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 742639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (742619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2704 + ... + 2965.

It is an arithmetic number, because the mean of its divisors is an integer number (187110).

2⁷⁴²⁶³⁹ is an apocalyptic number.

742639 is a deficient number, since it is larger than the sum of its proper divisors (5801).

742639 is a wasteful number, since it uses less digits than its factorization.

742639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5800.

The product of its digits is 9072, while the sum is 31.

The square root of 742639 is about 861.7650491868. The cubic root of 742639 is about 90.5578113169.

The spelling of 742639 in words is "seven hundred forty-two thousand, six hundred thirty-nine".