2125661 has 2 divisors, whose sum is σ = 2125662. Its totient is φ = 2125660.

The previous prime is 2125657. The next prime is 2125679. The reversal of 2125661 is 1665212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2088025 + 37636 = 1445^2 + 194^2 .

It is a cyclic number.

It is not a de Polignac number, because 2125661 - 2² = 2125657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2125601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1062830 + 1062831.

It is an arithmetic number, because the mean of its divisors is an integer number (1062831).

2^2125661 is an apocalyptic number.

It is an amenable number.

2125661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2125661 is an equidigital number, since it uses as much as digits as its factorization.

2125661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 2125661 is about 1457.9646772127. The cubic root of 2125661 is about 128.5774084814.

The spelling of 2125661 in words is "two million, one hundred twenty-five thousand, six hundred sixty-one".