6158591981 has 2 divisors, whose sum is σ = 6158591982. Its totient is φ = 6158591980.

The previous prime is 6158591977. The next prime is 6158592061. The reversal of 6158591981 is 1891958516.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4694305225 + 1464286756 = 68515^2 + 38266^2 .

It is a cyclic number.

It is not a de Polignac number, because 6158591981 - 2² = 6158591977 is a prime.

It is a super-2 number, since 2×6158591981² = 75856510376875008722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6158591911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3079295990 + 3079295991.

It is an arithmetic number, because the mean of its divisors is an integer number (3079295991).

Almost surely, 2^6158591981 is an apocalyptic number.

It is an amenable number.

6158591981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6158591981 is an equidigital number, since it uses as much as digits as its factorization.

6158591981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 777600, while the sum is 53.

The square root of 6158591981 is about 78476.6970571519. The cubic root of 6158591981 is about 1832.9916111924.

The spelling of 6158591981 in words is "six billion, one hundred fifty-eight million, five hundred ninety-one thousand, nine hundred eighty-one".