41643661 has 6 divisors (see below), whose sum is σ = 41873486. Its totient is φ = 41415000.

The previous prime is 41643647. The next prime is 41643677. The reversal of 41643661 is 16634614.

It can be written as a sum of positive squares in only one way, i.e., 39375625 + 2268036 = 6275^2 + 1506^2 .

It is a de Polignac number, because none of the positive numbers 2^k-41643661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (41643631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62671 + ... + 63331.

Almost surely, 2^41643661 is an apocalyptic number.

It is an amenable number.

41643661 is a deficient number, since it is larger than the sum of its proper divisors (229825).

41643661 is an frugal number, since it uses more digits than its factorization.

41643661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163 (or 912 counting only the distinct ones).

The product of its digits is 10368, while the sum is 31.

The square root of 41643661 is about 6453.1899863556. The cubic root of 41643661 is about 346.6168204753.

The spelling of 41643661 in words is "forty-one million, six hundred forty-three thousand, six hundred sixty-one".