1553561 has 2 divisors, whose sum is σ = 1553562. Its totient is φ = 1553560.

The previous prime is 1553557. The next prime is 1553567. The reversal of 1553561 is 1653551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1485961 + 67600 = 1219^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553561 - 2² = 1553557 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1553561.

It is not a weakly prime, because it can be changed into another prime (1553567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776780 + 776781.

It is an arithmetic number, because the mean of its divisors is an integer number (776781).

2^1553561 is an apocalyptic number.

It is an amenable number.

1553561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553561 is an equidigital number, since it uses as much as digits as its factorization.

1553561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2250, while the sum is 26.

The square root of 1553561 is about 1246.4192713529. The cubic root of 1553561 is about 115.8180113037.

The spelling of 1553561 in words is "one million, five hundred fifty-three thousand, five hundred sixty-one".