1971598513 has 2 divisors, whose sum is σ = 1971598514. Its totient is φ = 1971598512.

The previous prime is 1971598487. The next prime is 1971598549. The reversal of 1971598513 is 3158951791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1315367824 + 656230689 = 36268^2 + 25617^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1971598513 is a prime.

It is a super-2 number, since 2×1971598513² = 7774401392927622338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1971598313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985799256 + 985799257.

It is an arithmetic number, because the mean of its divisors is an integer number (985799257).

Almost surely, 2^1971598513 is an apocalyptic number.

It is an amenable number.

1971598513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971598513 is an equidigital number, since it uses as much as digits as its factorization.

1971598513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 340200, while the sum is 49.

The square root of 1971598513 is about 44402.6858759693. The cubic root of 1971598513 is about 1253.9286557024.

The spelling of 1971598513 in words is "one billion, nine hundred seventy-one million, five hundred ninety-eight thousand, five hundred thirteen".