1628881 has 2 divisors, whose sum is σ = 1628882. Its totient is φ = 1628880.

The previous prime is 1628873. The next prime is 1628897. The reversal of 1628881 is 1888261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 921600 + 707281 = 960^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 1628881 - 2³ = 1628873 is a prime.

It is a super-2 number, since 2×1628881² = 5306506624322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1628801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814440 + 814441.

It is an arithmetic number, because the mean of its divisors is an integer number (814441).

2^1628881 is an apocalyptic number.

It is an amenable number.

1628881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628881 is an equidigital number, since it uses as much as digits as its factorization.

1628881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6144, while the sum is 34.

The square root of 1628881 is about 1276.2762240205. The cubic root of 1628881 is about 117.6602551521.

The spelling of 1628881 in words is "one million, six hundred twenty-eight thousand, eight hundred eighty-one".