1620340621 has 8 divisors (see below), whose sum is σ = 1650751488. Its totient is φ = 1590054000.

The previous prime is 1620340619. The next prime is 1620340627. The reversal of 1620340621 is 1260430261.

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 1620340621 - 2¹ = 1620340619 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 (1620340627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4525 + ... + 57106.

It is an arithmetic number, because the mean of its divisors is an integer number (206343936).

Almost surely, 2^1620340621 is an apocalyptic number.

It is an amenable number.

1620340621 is a deficient number, since it is larger than the sum of its proper divisors (30410867).

1620340621 is an equidigital number, since it uses as much as digits as its factorization.

1620340621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62123.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1620340621 is about 40253.4547709883. The cubic root of 1620340621 is about 1174.5426005409.

Adding to 1620340621 its reverse (1260430261), we get a palindrome (2880770882).

The spelling of 1620340621 in words is "one billion, six hundred twenty million, three hundred forty thousand, six hundred twenty-one".