635666889 has 32 divisors (see below), whose sum is σ = 1003419648. Its totient is φ = 352872000.

The previous prime is 635666887. The next prime is 635666897. The reversal of 635666889 is 988666536.

It is not a de Polignac number, because 635666889 - 2¹ = 635666887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (635666881) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50544 + ... + 61854.

It is an arithmetic number, because the mean of its divisors is an integer number (31356864).

Almost surely, 2^635666889 is an apocalyptic number.

It is an amenable number.

635666889 is a deficient number, since it is larger than the sum of its proper divisors (367752759).

635666889 is a wasteful number, since it uses less digits than its factorization.

635666889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11469.

The product of its digits is 11197440, while the sum is 57.

The square root of 635666889 is about 25212.4352056679. The cubic root of 635666889 is about 859.8245942068.

The spelling of 635666889 in words is "six hundred thirty-five million, six hundred sixty-six thousand, eight hundred eighty-nine".