591991392557 has 2 divisors, whose sum is σ = 591991392558. Its totient is φ = 591991392556.

The previous prime is 591991392529. The next prime is 591991392569. The reversal of 591991392557 is 755293199195.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 384971852521 + 207019540036 = 620461^2 + 454994^2 .

It is a cyclic number.

It is not a de Polignac number, because 591991392557 - 2¹⁶ = 591991327021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 591991392493 and 591991392502.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (591991392757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 295995696278 + 295995696279.

It is an arithmetic number, because the mean of its divisors is an integer number (295995696279).

Almost surely, 2^591991392557 is an apocalyptic number.

It is an amenable number.

591991392557 is a deficient number, since it is larger than the sum of its proper divisors (1).

591991392557 is an equidigital number, since it uses as much as digits as its factorization.

591991392557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34445250, while the sum is 65.

The spelling of 591991392557 in words is "five hundred ninety-one billion, nine hundred ninety-one million, three hundred ninety-two thousand, five hundred fifty-seven".