1621057618 has 32 divisors (see below), whose sum is σ = 2675312640. Its totient is φ = 733257360.

The previous prime is 1621057609. The next prime is 1621057619. The reversal of 1621057618 is 8167501261.

It is not an unprimeable number, because it can be changed into a prime (1621057619) 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 15 ways as a sum of consecutive naturals, for example, 707671 + ... + 709957.

It is an arithmetic number, because the mean of its divisors is an integer number (83603520).

Almost surely, 2^1621057618 is an apocalyptic number.

1621057618 is a deficient number, since it is larger than the sum of its proper divisors (1054255022).

1621057618 is a wasteful number, since it uses less digits than its factorization.

1621057618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 1621057618 is about 40262.3598165830. The cubic root of 1621057618 is about 1174.7158191274.

Adding to 1621057618 its reverse (8167501261), we get a palindrome (9788558879).

The spelling of 1621057618 in words is "one billion, six hundred twenty-one million, fifty-seven thousand, six hundred eighteen".