2197561 has 2 divisors, whose sum is σ = 2197562. Its totient is φ = 2197560.

The previous prime is 2197537. The next prime is 2197567. The reversal of 2197561 is 1657912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1587600 + 609961 = 1260^2 + 781^2 .

It is a cyclic number.

It is not a de Polignac number, because 2197561 - 2⁹ = 2197049 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 (2197567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1098780 + 1098781.

It is an arithmetic number, because the mean of its divisors is an integer number (1098781).

2^2197561 is an apocalyptic number.

It is an amenable number.

2197561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2197561 is an equidigital number, since it uses as much as digits as its factorization.

2197561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3780, while the sum is 31.

The square root of 2197561 is about 1482.4172826839. The cubic root of 2197561 is about 130.0110641471.

The spelling of 2197561 in words is "two million, one hundred ninety-seven thousand, five hundred sixty-one".