636321442 has 4 divisors (see below), whose sum is σ = 954482166. Its totient is φ = 318160720.

The previous prime is 636321437. The next prime is 636321443. The reversal of 636321442 is 244123636.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 467035321 + 169286121 = 21611^2 + 13011^2 .

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 not an unprimeable number, because it can be changed into a prime (636321443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159080359 + ... + 159080362.

Almost surely, 2^636321442 is an apocalyptic number.

636321442 is a deficient number, since it is larger than the sum of its proper divisors (318160724).

636321442 is a wasteful number, since it uses less digits than its factorization.

636321442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318160723.

The product of its digits is 20736, while the sum is 31.

The square root of 636321442 is about 25225.4126229880. The cubic root of 636321442 is about 860.1196164969.

The spelling of 636321442 in words is "six hundred thirty-six million, three hundred twenty-one thousand, four hundred forty-two".