1621557159 has 8 divisors (see below), whose sum is σ = 2162426112. Its totient is φ = 1080863160.

The previous prime is 1621557149. The next prime is 1621557167. The reversal of 1621557159 is 9517551261.

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

It is not a de Polignac number, because 1621557159 - 2⁹ = 1621556647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1621557159.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621557149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20319 + ... + 60464.

It is an arithmetic number, because the mean of its divisors is an integer number (270303264).

Almost surely, 2^1621557159 is an apocalyptic number.

1621557159 is a deficient number, since it is larger than the sum of its proper divisors (540868953).

1621557159 is an equidigital number, since it uses as much as digits as its factorization.

1621557159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87477.

The product of its digits is 94500, while the sum is 42.

The square root of 1621557159 is about 40268.5629120285. The cubic root of 1621557159 is about 1174.8364725496.

The spelling of 1621557159 in words is "one billion, six hundred twenty-one million, five hundred fifty-seven thousand, one hundred fifty-nine".