636681742 has 4 divisors (see below), whose sum is σ = 955022616. Its totient is φ = 318340870.

The previous prime is 636681737. The next prime is 636681757. The reversal of 636681742 is 247186636.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159170434 + ... + 159170437.

It is an arithmetic number, because the mean of its divisors is an integer number (238755654).

Almost surely, 2^636681742 is an apocalyptic number.

636681742 is a deficient number, since it is larger than the sum of its proper divisors (318340874).

636681742 is a wasteful number, since it uses less digits than its factorization.

636681742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318340873.

The product of its digits is 290304, while the sum is 43.

The square root of 636681742 is about 25232.5532199974. The cubic root of 636681742 is about 860.2819257768.

The spelling of 636681742 in words is "six hundred thirty-six million, six hundred eighty-one thousand, seven hundred forty-two".