1561993441 has 8 divisors (see below), whose sum is σ = 1634137344. Its totient is φ = 1491470880.

The previous prime is 1561993427. The next prime is 1561993453. The reversal of 1561993441 is 1443991651.

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 1561993441 - 2¹¹ = 1561991393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561993421) 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 7 ways as a sum of consecutive naturals, for example, 403365 + ... + 407218.

It is an arithmetic number, because the mean of its divisors is an integer number (204267168).

Almost surely, 2^1561993441 is an apocalyptic number.

It is an amenable number.

1561993441 is a deficient number, since it is larger than the sum of its proper divisors (72143903).

1561993441 is an equidigital number, since it uses as much as digits as its factorization.

1561993441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810671.

The product of its digits is 116640, while the sum is 43.

The square root of 1561993441 is about 39522.0627118575. The cubic root of 1561993441 is about 1160.2717954575.

The spelling of 1561993441 in words is "one billion, five hundred sixty-one million, nine hundred ninety-three thousand, four hundred forty-one".