81580119437 has 2 divisors, whose sum is σ = 81580119438. Its totient is φ = 81580119436.

The previous prime is 81580119433. The next prime is 81580119449. The reversal of 81580119437 is 73491108518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52960277161 + 28619842276 = 230131^2 + 169174^2 .

It is a cyclic number.

It is not a de Polignac number, because 81580119437 - 2² = 81580119433 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81580119391 and 81580119400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81580119433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40790059718 + 40790059719.

It is an arithmetic number, because the mean of its divisors is an integer number (40790059719).

Almost surely, 2^81580119437 is an apocalyptic number.

It is an amenable number.

81580119437 is a deficient number, since it is larger than the sum of its proper divisors (1).

81580119437 is an equidigital number, since it uses as much as digits as its factorization.

81580119437 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 241920, while the sum is 47.

The spelling of 81580119437 in words is "eighty-one billion, five hundred eighty million, one hundred nineteen thousand, four hundred thirty-seven".