637640145 has 24 divisors (see below), whose sum is σ = 1105866216. Its totient is φ = 339883008.

The previous prime is 637640141. The next prime is 637640161. The reversal of 637640145 is 541046736.

It is a happy number.

637640145 is a `hidden beast` number, since 6 + 3 + 7 + 640 + 1 + 4 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 305270784 + 332369361 = 17472^2 + 18231^2 .

It is not a de Polignac number, because 637640145 - 2² = 637640141 is a prime.

It is not an unprimeable number, because it can be changed into a prime (637640141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116899 + ... + 122231.

It is an arithmetic number, because the mean of its divisors is an integer number (46077759).

Almost surely, 2^637640145 is an apocalyptic number.

It is an amenable number.

637640145 is a deficient number, since it is larger than the sum of its proper divisors (468226071).

637640145 is a wasteful number, since it uses less digits than its factorization.

637640145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8001 (or 7998 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 637640145 is about 25251.5374779438. The cubic root of 637640145 is about 860.7133728470.

The spelling of 637640145 in words is "six hundred thirty-seven million, six hundred forty thousand, one hundred forty-five".