205551155749 has 2 divisors, whose sum is σ = 205551155750. Its totient is φ = 205551155748.

The previous prime is 205551155713. The next prime is 205551155759. The reversal of 205551155749 is 947551155502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141368480100 + 64182675649 = 375990^2 + 253343^2 .

It is a cyclic number.

It is not a de Polignac number, because 205551155749 - 2²⁷ = 205416938021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205551155759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102775577874 + 102775577875.

It is an arithmetic number, because the mean of its divisors is an integer number (102775577875).

Almost surely, 2^205551155749 is an apocalyptic number.

It is an amenable number.

205551155749 is a deficient number, since it is larger than the sum of its proper divisors (1).

205551155749 is an equidigital number, since it uses as much as digits as its factorization.

205551155749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1575000, while the sum is 49.

The spelling of 205551155749 in words is "two hundred five billion, five hundred fifty-one million, one hundred fifty-five thousand, seven hundred forty-nine".