261262555 has 4 divisors (see below), whose sum is σ = 313515072. Its totient is φ = 209010040.

The previous prime is 261262553. The next prime is 261262567. The reversal of 261262555 is 555262162.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 261262555 - 2¹ = 261262553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261262555.

It is not an unprimeable number, because it can be changed into a prime (261262553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26126251 + ... + 26126260.

It is an arithmetic number, because the mean of its divisors is an integer number (78378768).

Almost surely, 2^261262555 is an apocalyptic number.

261262555 is a deficient number, since it is larger than the sum of its proper divisors (52252517).

261262555 is an equidigital number, since it uses as much as digits as its factorization.

261262555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52252516.

The product of its digits is 36000, while the sum is 34.

The square root of 261262555 is about 16163.6182521117. The cubic root of 261262555 is about 639.2818727322.

The spelling of 261262555 in words is "two hundred sixty-one million, two hundred sixty-two thousand, five hundred fifty-five".