1621366189 has 4 divisors (see below), whose sum is σ = 1626900156. Its totient is φ = 1615832224.

The previous prime is 1621366183. The next prime is 1621366199. The reversal of 1621366189 is 9816631261.

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 1390022089 + 231344100 = 37283^2 + 15210^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621366189 - 2⁹ = 1621365677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621366183) 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 3 ways as a sum of consecutive naturals, for example, 2766544 + ... + 2767129.

It is an arithmetic number, because the mean of its divisors is an integer number (406725039).

Almost surely, 2^1621366189 is an apocalyptic number.

It is an amenable number.

1621366189 is a deficient number, since it is larger than the sum of its proper divisors (5533967).

1621366189 is an equidigital number, since it uses as much as digits as its factorization.

1621366189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5533966.

The product of its digits is 93312, while the sum is 43.

The square root of 1621366189 is about 40266.1916376506. The cubic root of 1621366189 is about 1174.7903507652.

The spelling of 1621366189 in words is "one billion, six hundred twenty-one million, three hundred sixty-six thousand, one hundred eighty-nine".