646542 has 40 divisors (see below), whose sum is σ = 1565256. Its totient is φ = 198288.

The previous prime is 646537. The next prime is 646543. The reversal of 646542 is 245646.

It is a happy number.

646542 is a `hidden beast` number, since 6 + 4 + 654 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646542.

It is not an unprimeable number, because it can be changed into a prime (646543) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1953 + ... + 2259.

2⁶⁴⁶⁵⁴² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (782628).

646542 is an abundant number, since it is smaller than the sum of its proper divisors (918714).

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

646542 is a wasteful number, since it uses less digits than its factorization.

646542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334 (or 325 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 646542 is about 804.0783543909. The cubic root of 646542 is about 86.4700242509.

The spelling of 646542 in words is "six hundred forty-six thousand, five hundred forty-two".