1561741 has 2 divisors, whose sum is σ = 1561742. Its totient is φ = 1561740.

The previous prime is 1561727. The next prime is 1561753. The reversal of 1561741 is 1471651.

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., 1512900 + 48841 = 1230^2 + 221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561741 is a prime.

1561741 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780870 + 780871.

It is an arithmetic number, because the mean of its divisors is an integer number (780871).

2^1561741 is an apocalyptic number.

It is an amenable number.

1561741 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561741 is an equidigital number, since it uses as much as digits as its factorization.

1561741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 25.

The square root of 1561741 is about 1249.6963631219. The cubic root of 1561741 is about 116.0209286456.

The spelling of 1561741 in words is "one million, five hundred sixty-one thousand, seven hundred forty-one".