261338061 has 4 divisors (see below), whose sum is σ = 348450752. Its totient is φ = 174225372.

The previous prime is 261338039. The next prime is 261338101. The reversal of 261338061 is 160833162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 261338061 - 2¹⁸ = 261075917 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 (261338461) 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, 43556341 + ... + 43556346.

It is an arithmetic number, because the mean of its divisors is an integer number (87112688).

Almost surely, 2^261338061 is an apocalyptic number.

It is an amenable number.

261338061 is a deficient number, since it is larger than the sum of its proper divisors (87112691).

261338061 is an equidigital number, since it uses as much as digits as its factorization.

261338061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87112690.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 261338061 is about 16165.9537609137. The cubic root of 261338061 is about 639.3434518689.

The spelling of 261338061 in words is "two hundred sixty-one million, three hundred thirty-eight thousand, sixty-one".