1621568741 has 8 divisors (see below), whose sum is σ = 1753554264. Its totient is φ = 1490618880.

The previous prime is 1621568723. The next prime is 1621568777. The reversal of 1621568741 is 1478651261.

It can be written as a sum of positive squares in 4 ways, for example, as 156975841 + 1464592900 = 12529^2 + 38270^2 .

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 1621568741 - 2¹⁴ = 1621552357 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 (1621568791) 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, 255656 + ... + 261921.

It is an arithmetic number, because the mean of its divisors is an integer number (219194283).

Almost surely, 2^1621568741 is an apocalyptic number.

It is an amenable number.

1621568741 is a deficient number, since it is larger than the sum of its proper divisors (131985523).

1621568741 is a wasteful number, since it uses less digits than its factorization.

1621568741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517831.

The product of its digits is 80640, while the sum is 41.

The square root of 1621568741 is about 40268.7067212246. The cubic root of 1621568741 is about 1174.8392696396.

The spelling of 1621568741 in words is "one billion, six hundred twenty-one million, five hundred sixty-eight thousand, seven hundred forty-one".