1561955 has 8 divisors (see below), whose sum is σ = 1925232. Its totient is φ = 1215648.

The previous prime is 1561919. The next prime is 1562051. The reversal of 1561955 is 5591651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1561955 - 2⁶ = 1561891 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4037 + ... + 4406.

It is an arithmetic number, because the mean of its divisors is an integer number (240654).

2^1561955 is an apocalyptic number.

1561955 is a deficient number, since it is larger than the sum of its proper divisors (363277).

1561955 is an equidigital number, since it uses as much as digits as its factorization.

1561955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8485.

The product of its digits is 6750, while the sum is 32.

The square root of 1561955 is about 1249.7819809871. The cubic root of 1561955 is about 116.0262277199.

The spelling of 1561955 in words is "one million, five hundred sixty-one thousand, nine hundred fifty-five".