1555121 has 4 divisors (see below), whose sum is σ = 1558512. Its totient is φ = 1551732.

The previous prime is 1555117. The next prime is 1555123. The reversal of 1555121 is 1215551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1215551 = 17 ⋅71503.

It is a cyclic number.

It is not a de Polignac number, because 1555121 - 2² = 1555117 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1555093 and 1555102.

It is not an unprimeable number, because it can be changed into a prime (1555123) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 875 + ... + 1968.

It is an arithmetic number, because the mean of its divisors is an integer number (389628).

2^1555121 is an apocalyptic number.

It is an amenable number.

1555121 is a deficient number, since it is larger than the sum of its proper divisors (3391).

1555121 is an equidigital number, since it uses as much as digits as its factorization.

1555121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3390.

The product of its digits is 250, while the sum is 20.

The square root of 1555121 is about 1247.0449069701. The cubic root of 1555121 is about 115.8567643483.

The spelling of 1555121 in words is "one million, five hundred fifty-five thousand, one hundred twenty-one".