636506091 has 12 divisors (see below), whose sum is σ = 990120768. Its totient is φ = 391695984.

The previous prime is 636506089. The next prime is 636506107. The reversal of 636506091 is 190605636.

636506091 is a `hidden beast` number, since 63 + 6 + 506 + 0 + 91 = 666.

It is not a de Polignac number, because 636506091 - 2¹ = 636506089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (636506011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2719995 + ... + 2720228.

It is an arithmetic number, because the mean of its divisors is an integer number (82510064).

Almost surely, 2^636506091 is an apocalyptic number.

636506091 is a deficient number, since it is larger than the sum of its proper divisors (353614677).

636506091 is a wasteful number, since it uses less digits than its factorization.

636506091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5440242 (or 5440239 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 636506091 is about 25229.0723372858. The cubic root of 636506091 is about 860.2028055147.

The spelling of 636506091 in words is "six hundred thirty-six million, five hundred six thousand, ninety-one".