20255591 has 2 divisors, whose sum is σ = 20255592. Its totient is φ = 20255590.

The previous prime is 20255567. The next prime is 20255603. The reversal of 20255591 is 19555202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20255591 - 2⁶ = 20255527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20258591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10127795 + 10127796.

It is an arithmetic number, because the mean of its divisors is an integer number (10127796).

Almost surely, 2^20255591 is an apocalyptic number.

20255591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20255591 is an equidigital number, since it uses as much as digits as its factorization.

20255591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 20255591 is about 4500.6211793485. The cubic root of 20255591 is about 272.5931718541.

The spelling of 20255591 in words is "twenty million, two hundred fifty-five thousand, five hundred ninety-one".