657642 has 16 divisors (see below), whose sum is σ = 1346400. Its totient is φ = 214032.

The previous prime is 657617. The next prime is 657649. The reversal of 657642 is 246756.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (657649) by changing a digit.

657642 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1017 + ... + 1532.

It is an arithmetic number, because the mean of its divisors is an integer number (84150).

2⁶⁵⁷⁶⁴² is an apocalyptic number.

657642 is an abundant number, since it is smaller than the sum of its proper divisors (688758).

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

657642 is a wasteful number, since it uses less digits than its factorization.

657642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2597.

The product of its digits is 10080, while the sum is 30.

The square root of 657642 is about 810.9512932353. The cubic root of 657642 is about 86.9620656393.

The spelling of 657642 in words is "six hundred fifty-seven thousand, six hundred forty-two".