8415661 has 2 divisors, whose sum is σ = 8415662. Its totient is φ = 8415660.

The previous prime is 8415653. The next prime is 8415691. The reversal of 8415661 is 1665148.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5546025 + 2869636 = 2355^2 + 1694^2 .

It is a cyclic number.

It is not a de Polignac number, because 8415661 - 2³ = 8415653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8415611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4207830 + 4207831.

It is an arithmetic number, because the mean of its divisors is an integer number (4207831).

Almost surely, 2^8415661 is an apocalyptic number.

It is an amenable number.

8415661 is a deficient number, since it is larger than the sum of its proper divisors (1).

8415661 is an equidigital number, since it uses as much as digits as its factorization.

8415661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 31.

The square root of 8415661 is about 2900.9758702892. The cubic root of 8415661 is about 203.4055245469.

The spelling of 8415661 in words is "eight million, four hundred fifteen thousand, six hundred sixty-one".