521140591 has 2 divisors, whose sum is σ = 521140592. Its totient is φ = 521140590.

The previous prime is 521140579. The next prime is 521140637. The reversal of 521140591 is 195041125.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 521140591 - 2¹⁷ = 521009519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521140561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260570295 + 260570296.

It is an arithmetic number, because the mean of its divisors is an integer number (260570296).

Almost surely, 2^521140591 is an apocalyptic number.

521140591 is a deficient number, since it is larger than the sum of its proper divisors (1).

521140591 is an equidigital number, since it uses as much as digits as its factorization.

521140591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 28.

The square root of 521140591 is about 22828.5039150620. The cubic root of 521140591 is about 804.7326715442.

It can be divided in two parts, 521140 and 591, that added together give a triangular number (521731 = T₁₀₂₁).

The spelling of 521140591 in words is "five hundred twenty-one million, one hundred forty thousand, five hundred ninety-one".