40563661 has 2 divisors, whose sum is σ = 40563662. Its totient is φ = 40563660.

The previous prime is 40563659. The next prime is 40563703. The reversal of 40563661 is 16636504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28355625 + 12208036 = 5325^2 + 3494^2 .

It is a cyclic number.

It is not a de Polignac number, because 40563661 - 2¹ = 40563659 is a prime.

Together with 40563659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40563631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20281830 + 20281831.

It is an arithmetic number, because the mean of its divisors is an integer number (20281831).

Almost surely, 2^40563661 is an apocalyptic number.

It is an amenable number.

40563661 is a deficient number, since it is larger than the sum of its proper divisors (1).

40563661 is an equidigital number, since it uses as much as digits as its factorization.

40563661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 40563661 is about 6368.9607472491. The cubic root of 40563661 is about 343.5941135164.

The spelling of 40563661 in words is "forty million, five hundred sixty-three thousand, six hundred sixty-one".