1561271 has 4 divisors (see below), whose sum is σ = 1564632. Its totient is φ = 1557912.

The previous prime is 1561267. The next prime is 1561279. The reversal of 1561271 is 1721651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1561271 - 2² = 1561267 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561279) 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, 845 + ... + 1958.

It is an arithmetic number, because the mean of its divisors is an integer number (391158).

2^1561271 is an apocalyptic number.

1561271 is a deficient number, since it is larger than the sum of its proper divisors (3361).

1561271 is an equidigital number, since it uses as much as digits as its factorization.

1561271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3360.

The product of its digits is 420, while the sum is 23.

The square root of 1561271 is about 1249.5083032937. The cubic root of 1561271 is about 116.0092887924.

The spelling of 1561271 in words is "one million, five hundred sixty-one thousand, two hundred seventy-one".