1628261 has 2 divisors, whose sum is σ = 1628262. Its totient is φ = 1628260.

The previous prime is 1628227. The next prime is 1628279.

1628261 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1012036 + 616225 = 1006^2 + 785^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 1628261 - 2⁶ = 1628197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 1628261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1628161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814130 + 814131.

It is an arithmetic number, because the mean of its divisors is an integer number (814131).

2^1628261 is an apocalyptic number.

It is an amenable number.

1628261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628261 is an equidigital number, since it uses as much as digits as its factorization.

1628261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 26.

The square root of 1628261 is about 1276.0333067753. The cubic root of 1628261 is about 117.6453249401.

The spelling of 1628261 in words is "one million, six hundred twenty-eight thousand, two hundred sixty-one".