1561919 has 2 divisors, whose sum is σ = 1561920. Its totient is φ = 1561918.

The previous prime is 1561891. The next prime is 1562051. The reversal of 1561919 is 9191651.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561919 - 2¹² = 1557823 is a prime.

It is a super-2 number, since 2×1561919² = 4879181925122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780959 + 780960.

It is an arithmetic number, because the mean of its divisors is an integer number (780960).

2^1561919 is an apocalyptic number.

1561919 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561919 is an equidigital number, since it uses as much as digits as its factorization.

1561919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2430, while the sum is 32.

The square root of 1561919 is about 1249.7675783921. The cubic root of 1561919 is about 116.0253363207.

The spelling of 1561919 in words is "one million, five hundred sixty-one thousand, nine hundred nineteen".