20531203591 has 2 divisors, whose sum is σ = 20531203592. Its totient is φ = 20531203590.

The previous prime is 20531203513. The next prime is 20531203607. The reversal of 20531203591 is 19530213502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20531203591 - 2¹⁹ = 20530679303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20531201591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10265601795 + 10265601796.

It is an arithmetic number, because the mean of its divisors is an integer number (10265601796).

Almost surely, 2^20531203591 is an apocalyptic number.

20531203591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20531203591 is an equidigital number, since it uses as much as digits as its factorization.

20531203591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8100, while the sum is 31.

The spelling of 20531203591 in words is "twenty billion, five hundred thirty-one million, two hundred three thousand, five hundred ninety-one".