1621289689 has 8 divisors (see below), whose sum is σ = 1677645000. Its totient is φ = 1564964352.

The previous prime is 1621289687. The next prime is 1621289701. The reversal of 1621289689 is 9869821261.

It can be written as a sum of positive squares in 4 ways, for example, as 12638025 + 1608651664 = 3555^2 + 40108^2 .

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

It is not a de Polignac number, because 1621289689 - 2¹ = 1621289687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621289687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208137 + ... + 215785.

It is an arithmetic number, because the mean of its divisors is an integer number (209705625).

Almost surely, 2^1621289689 is an apocalyptic number.

It is an amenable number.

1621289689 is a deficient number, since it is larger than the sum of its proper divisors (56355311).

1621289689 is an equidigital number, since it uses as much as digits as its factorization.

1621289689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14987.

The product of its digits is 746496, while the sum is 52.

The square root of 1621289689 is about 40265.2416980204. The cubic root of 1621289689 is about 1174.7718739860.

The spelling of 1621289689 in words is "one billion, six hundred twenty-one million, two hundred eighty-nine thousand, six hundred eighty-nine".