1621366636 has 12 divisors (see below), whose sum is σ = 3004297128. Its totient is φ = 762996032.

The previous prime is 1621366583. The next prime is 1621366651. The reversal of 1621366636 is 6366631261.

It is an unprimeable number.

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, 11921746 + ... + 11921881.

It is an arithmetic number, because the mean of its divisors is an integer number (250358094).

Almost surely, 2^1621366636 is an apocalyptic number.

It is an amenable number.

1621366636 is a deficient number, since it is larger than the sum of its proper divisors (1382930492).

1621366636 is a wasteful number, since it uses less digits than its factorization.

1621366636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23843648 (or 23843646 counting only the distinct ones).

The product of its digits is 139968, while the sum is 40.

The square root of 1621366636 is about 40266.1971882123. The cubic root of 1621366636 is about 1174.7904587258.

Adding to 1621366636 its reverse (6366631261), we get a palindrome (7987997897).

The spelling of 1621366636 in words is "one billion, six hundred twenty-one million, three hundred sixty-six thousand, six hundred thirty-six".