1553551 has 4 divisors (see below), whose sum is σ = 1575504. Its totient is φ = 1531600.

The previous prime is 1553543. The next prime is 1553557.

1553551 is nontrivially palindromic in base 10.

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 1553551 - 2³ = 1553543 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 (1553557) 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, 10870 + ... + 11011.

It is an arithmetic number, because the mean of its divisors is an integer number (393876).

2^1553551 is an apocalyptic number.

1553551 is a deficient number, since it is larger than the sum of its proper divisors (21953).

1553551 is an equidigital number, since it uses as much as digits as its factorization.

1553551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21952.

The product of its digits is 1875, while the sum is 25.

The square root of 1553551 is about 1246.4152598552. The cubic root of 1553551 is about 115.8177628031.

The spelling of 1553551 in words is "one million, five hundred fifty-three thousand, five hundred fifty-one".