1561457 has 2 divisors, whose sum is σ = 1561458. Its totient is φ = 1561456.

The previous prime is 1561453. The next prime is 1561463. The reversal of 1561457 is 7541651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 802816 + 758641 = 896^2 + 871^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561457 - 2² = 1561453 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1561453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780728 + 780729.

It is an arithmetic number, because the mean of its divisors is an integer number (780729).

2^1561457 is an apocalyptic number.

It is an amenable number.

1561457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561457 is an equidigital number, since it uses as much as digits as its factorization.

1561457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4200, while the sum is 29.

The square root of 1561457 is about 1249.5827303544. The cubic root of 1561457 is about 116.0138954817.

The spelling of 1561457 in words is "one million, five hundred sixty-one thousand, four hundred fifty-seven".