1561947 has 4 divisors (see below), whose sum is σ = 2082600. Its totient is φ = 1041296.

The previous prime is 1561919. The next prime is 1562051. The reversal of 1561947 is 7491651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7491651 = 3 ⋅2497217.

It is a cyclic number.

It is not a de Polignac number, because 1561947 - 2⁶ = 1561883 is a prime.

It is a D-number.

1561947 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1561247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260322 + ... + 260327.

It is an arithmetic number, because the mean of its divisors is an integer number (520650).

2^1561947 is an apocalyptic number.

1561947 is a deficient number, since it is larger than the sum of its proper divisors (520653).

1561947 is an equidigital number, since it uses as much as digits as its factorization.

1561947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520652.

The product of its digits is 7560, while the sum is 33.

The square root of 1561947 is about 1249.7787804248. The cubic root of 1561947 is about 116.0260296323.

The spelling of 1561947 in words is "one million, five hundred sixty-one thousand, nine hundred forty-seven".