261226015 has 4 divisors (see below), whose sum is σ = 313471224. Its totient is φ = 208980808.

The previous prime is 261226013. The next prime is 261226027. The reversal of 261226015 is 510622162.

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

It is a cyclic number.

It is not a de Polignac number, because 261226015 - 2¹ = 261226013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261226013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26122597 + ... + 26122606.

It is an arithmetic number, because the mean of its divisors is an integer number (78367806).

Almost surely, 2^261226015 is an apocalyptic number.

261226015 is a deficient number, since it is larger than the sum of its proper divisors (52245209).

261226015 is an equidigital number, since it uses as much as digits as its factorization.

261226015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52245208.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 261226015 is about 16162.4878963605. The cubic root of 261226015 is about 639.2520681694.

Adding to 261226015 its reverse (510622162), we get a palindrome (771848177).

The spelling of 261226015 in words is "two hundred sixty-one million, two hundred twenty-six thousand, fifteen".