1001983561 has 4 divisors (see below), whose sum is σ = 1003145472. Its totient is φ = 1000821652.

The previous prime is 1001983469. The next prime is 1001983583. The reversal of 1001983561 is 1653891001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1001983561 - 2⁹ = 1001983049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1001983261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 579661 + ... + 581386.

It is an arithmetic number, because the mean of its divisors is an integer number (250786368).

Almost surely, 2^1001983561 is an apocalyptic number.

It is an amenable number.

1001983561 is a deficient number, since it is larger than the sum of its proper divisors (1161911).

1001983561 is an equidigital number, since it uses as much as digits as its factorization.

1001983561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1161910.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 1001983561 is about 31654.1239177457. The cubic root of 1001983561 is about 1000.6607503129.

The spelling of 1001983561 in words is "one billion, one million, nine hundred eighty-three thousand, five hundred sixty-one".