909638661 has 16 divisors (see below), whose sum is σ = 1332195840. Its totient is φ = 549529200.

The previous prime is 909638659. The next prime is 909638683. The reversal of 909638661 is 166836909.

It is not a de Polignac number, because 909638661 - 2¹ = 909638659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 909638661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (909638761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 345615 + ... + 348236.

It is an arithmetic number, because the mean of its divisors is an integer number (83262240).

Almost surely, 2^909638661 is an apocalyptic number.

It is an amenable number.

909638661 is a deficient number, since it is larger than the sum of its proper divisors (422557179).

909638661 is a wasteful number, since it uses less digits than its factorization.

909638661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693896.

The product of its (nonzero) digits is 419904, while the sum is 48.

The square root of 909638661 is about 30160.2165277373. The cubic root of 909638661 is about 968.9238289748.

The spelling of 909638661 in words is "nine hundred nine million, six hundred thirty-eight thousand, six hundred sixty-one".