1975981913 has 4 divisors (see below), whose sum is σ = 1999789008. Its totient is φ = 1952174820.

The previous prime is 1975981879. The next prime is 1975981919. The reversal of 1975981913 is 3191895791.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3191895791 = 7 ⋅455985113.

It is a cyclic number.

It is not a de Polignac number, because 1975981913 - 2²⁴ = 1959204697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1975981919) 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, 11903423 + ... + 11903588.

It is an arithmetic number, because the mean of its divisors is an integer number (499947252).

Almost surely, 2^1975981913 is an apocalyptic number.

It is an amenable number.

1975981913 is a deficient number, since it is larger than the sum of its proper divisors (23807095).

1975981913 is an equidigital number, since it uses as much as digits as its factorization.

1975981913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23807094.

The product of its digits is 612360, while the sum is 53.

The square root of 1975981913 is about 44452.0180981696. The cubic root of 1975981913 is about 1254.8572427472.

The spelling of 1975981913 in words is "one billion, nine hundred seventy-five million, nine hundred eighty-one thousand, nine hundred thirteen".