1561519 has 2 divisors, whose sum is σ = 1561520. Its totient is φ = 1561518.

The previous prime is 1561499. The next prime is 1561529. The reversal of 1561519 is 9151651.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561519 is a prime.

It is a super-2 number, since 2×1561519² = 4876683174722, which contains 22 as substring.

It is equal to p₁₁₈₄₇₇ and since 1561519 and 118477 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780759 + 780760.

It is an arithmetic number, because the mean of its divisors is an integer number (780760).

2^1561519 is an apocalyptic number.

1561519 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561519 is an equidigital number, since it uses as much as digits as its factorization.

1561519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1350, while the sum is 28.

The square root of 1561519 is about 1249.6075383896. The cubic root of 1561519 is about 116.0154309634.

It can be divided in two parts, 1561 and 519, that added together give a triangular number (2080 = T₆₄).

The spelling of 1561519 in words is "one million, five hundred sixty-one thousand, five hundred nineteen".