40189661 has 2 divisors, whose sum is σ = 40189662. Its totient is φ = 40189660.

The previous prime is 40189637. The next prime is 40189663. The reversal of 40189661 is 16698104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29365561 + 10824100 = 5419^2 + 3290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40189661 is a prime.

Together with 40189663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40189663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20094830 + 20094831.

It is an arithmetic number, because the mean of its divisors is an integer number (20094831).

Almost surely, 2^40189661 is an apocalyptic number.

It is an amenable number.

40189661 is a deficient number, since it is larger than the sum of its proper divisors (1).

40189661 is an equidigital number, since it uses as much as digits as its factorization.

40189661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 40189661 is about 6339.5316073035. The cubic root of 40189661 is about 342.5348635191.

The spelling of 40189661 in words is "forty million, one hundred eighty-nine thousand, six hundred sixty-one".