1621440446557 has 8 divisors (see below), whose sum is σ = 1627268832000. Its totient is φ = 1615620220704.

The previous prime is 1621440446539. The next prime is 1621440446567. The reversal of 1621440446557 is 7556440441261.

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

It is a cyclic number.

It is not a de Polignac number, because 1621440446557 - 2⁷ = 1621440446429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1621440446557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621440446567) 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, 1641613 + ... + 2436754.

It is an arithmetic number, because the mean of its divisors is an integer number (203408604000).

Almost surely, 2^{1621440446557} is an apocalyptic number.

It is an amenable number.

1621440446557 is a deficient number, since it is larger than the sum of its proper divisors (5828385443).

1621440446557 is a wasteful number, since it uses less digits than its factorization.

1621440446557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4079795.

The product of its (nonzero) digits is 3225600, while the sum is 49.

The spelling of 1621440446557 in words is "one trillion, six hundred twenty-one billion, four hundred forty million, four hundred forty-six thousand, five hundred fifty-seven".