1628891 has 8 divisors (see below), whose sum is σ = 1786224. Its totient is φ = 1473120.

The previous prime is 1628881. The next prime is 1628897. The reversal of 1628891 is 1988261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1628891 - 2¹⁰ = 1627867 is a prime.

It is an Ulam number.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (1628897) 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 7 ways as a sum of consecutive naturals, for example, 3905 + ... + 4301.

It is an arithmetic number, because the mean of its divisors is an integer number (223278).

2^1628891 is an apocalyptic number.

1628891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1628891 is a deficient number, since it is larger than the sum of its proper divisors (157333).

1628891 is a wasteful number, since it uses less digits than its factorization.

1628891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781.

The product of its digits is 6912, while the sum is 35.

The square root of 1628891 is about 1276.2801416617. The cubic root of 1628891 is about 117.6604959309.

The spelling of 1628891 in words is "one million, six hundred twenty-eight thousand, eight hundred ninety-one".