1897561 has 2 divisors, whose sum is σ = 1897562. Its totient is φ = 1897560.

The previous prime is 1897537. The next prime is 1897573. The reversal of 1897561 is 1657981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1849600 + 47961 = 1360^2 + 219^2 .

It is a cyclic number.

It is not a de Polignac number, because 1897561 - 2⁵ = 1897529 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1897561.

It is not a weakly prime, because it can be changed into another prime (1897361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 948780 + 948781.

It is an arithmetic number, because the mean of its divisors is an integer number (948781).

2^1897561 is an apocalyptic number.

It is an amenable number.

1897561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1897561 is an equidigital number, since it uses as much as digits as its factorization.

1897561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 37.

The square root of 1897561 is about 1377.5198728149. The cubic root of 1897561 is about 123.8032128393.

It can be divided in two parts, 189 and 7561, that added together give a triangular number (7750 = T₁₂₄).

The spelling of 1897561 in words is "one million, eight hundred ninety-seven thousand, five hundred sixty-one".