1015661 has 2 divisors, whose sum is σ = 1015662. Its totient is φ = 1015660.

The previous prime is 1015627. The next prime is 1015691. The reversal of 1015661 is 1665101.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 649636 + 366025 = 806^2 + 605^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1015661 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 (1015601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 507830 + 507831.

It is an arithmetic number, because the mean of its divisors is an integer number (507831).

2^1015661 is an apocalyptic number.

It is an amenable number.

1015661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1015661 is an equidigital number, since it uses as much as digits as its factorization.

1015661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 1015661 is about 1007.8000793808. The cubic root of 1015661 is about 100.5193316112.

The spelling of 1015661 in words is "one million, fifteen thousand, six hundred sixty-one".