1561423 has 2 divisors, whose sum is σ = 1561424. Its totient is φ = 1561422.

The previous prime is 1561421. The next prime is 1561429. The reversal of 1561423 is 3241651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561423 - 2¹ = 1561421 is a prime.

Together with 1561421, it forms a pair of twin primes.

1561423 is a lucky number.

It is equal to p₁₁₈₄₇₁ and since 1561423 and 118471 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 1561394 and 1561403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780711 + 780712.

It is an arithmetic number, because the mean of its divisors is an integer number (780712).

2^1561423 is an apocalyptic number.

1561423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561423 is an equidigital number, since it uses as much as digits as its factorization.

1561423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 22.

The square root of 1561423 is about 1249.5691257389. The cubic root of 1561423 is about 116.0130534260.

The spelling of 1561423 in words is "one million, five hundred sixty-one thousand, four hundred twenty-three".