265778551 has 2 divisors, whose sum is σ = 265778552. Its totient is φ = 265778550.

The previous prime is 265778543. The next prime is 265778567. The reversal of 265778551 is 155877562.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 265778551 - 2³ = 265778543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (265778581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132889275 + 132889276.

It is an arithmetic number, because the mean of its divisors is an integer number (132889276).

Almost surely, 2^265778551 is an apocalyptic number.

265778551 is a deficient number, since it is larger than the sum of its proper divisors (1).

265778551 is an equidigital number, since it uses as much as digits as its factorization.

265778551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 588000, while the sum is 46.

The square root of 265778551 is about 16302.7160620554. The cubic root of 265778551 is about 642.9442397994.

The spelling of 265778551 in words is "two hundred sixty-five million, seven hundred seventy-eight thousand, five hundred fifty-one".