1557109 has 2 divisors, whose sum is σ = 1557110. Its totient is φ = 1557108.

The previous prime is 1557103. The next prime is 1557113. The reversal of 1557109 is 9017551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 956484 + 600625 = 978^2 + 775^2 .

It is a cyclic number.

It is not a de Polignac number, because 1557109 - 2¹¹ = 1555061 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 (1557103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 778554 + 778555.

It is an arithmetic number, because the mean of its divisors is an integer number (778555).

2^1557109 is an apocalyptic number.

It is an amenable number.

1557109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1557109 is an equidigital number, since it uses as much as digits as its factorization.

1557109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1575, while the sum is 28.

The square root of 1557109 is about 1247.8417367599. The cubic root of 1557109 is about 115.9061120994.

The spelling of 1557109 in words is "one million, five hundred fifty-seven thousand, one hundred nine".