7543661 has 2 divisors, whose sum is σ = 7543662. Its totient is φ = 7543660.

The previous prime is 7543651. The next prime is 7543709. The reversal of 7543661 is 1663457.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6400900 + 1142761 = 2530^2 + 1069^2 .

It is an emirp because it is prime and its reverse (1663457) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7543661 - 2¹⁸ = 7281517 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7543651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3771830 + 3771831.

It is an arithmetic number, because the mean of its divisors is an integer number (3771831).

Almost surely, 2^7543661 is an apocalyptic number.

It is an amenable number.

7543661 is a deficient number, since it is larger than the sum of its proper divisors (1).

7543661 is an equidigital number, since it uses as much as digits as its factorization.

7543661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 32.

The square root of 7543661 is about 2746.5725914310. The cubic root of 7543661 is about 196.1224852198.

The spelling of 7543661 in words is "seven million, five hundred forty-three thousand, six hundred sixty-one".