1628920889 has 4 divisors (see below), whose sum is σ = 1629218340. Its totient is φ = 1628623440.

The previous prime is 1628920879. The next prime is 1628920897. The reversal of 1628920889 is 9880298261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 560742400 + 1068178489 = 23680^2 + 32683^2 .

It is a cyclic number.

It is not a de Polignac number, because 1628920889 - 2¹⁶ = 1628855353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1628920889.

It is not an unprimeable number, because it can be changed into a prime (1628920859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140354 + ... + 151515.

It is an arithmetic number, because the mean of its divisors is an integer number (407304585).

Almost surely, 2^1628920889 is an apocalyptic number.

It is an amenable number.

1628920889 is a deficient number, since it is larger than the sum of its proper divisors (297451).

1628920889 is an equidigital number, since it uses as much as digits as its factorization.

1628920889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297450.

The product of its (nonzero) digits is 995328, while the sum is 53.

The square root of 1628920889 is about 40359.8920836020. The cubic root of 1628920889 is about 1176.6121558885.

The spelling of 1628920889 in words is "one billion, six hundred twenty-eight million, nine hundred twenty thousand, eight hundred eighty-nine".