261351541 has 4 divisors (see below), whose sum is σ = 285110784. Its totient is φ = 237592300.

The previous prime is 261351521. The next prime is 261351569. The reversal of 261351541 is 145153162.

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 261351541 - 2¹⁹ = 260827253 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 (261351521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11879605 + ... + 11879626.

It is an arithmetic number, because the mean of its divisors is an integer number (71277696).

Almost surely, 2^261351541 is an apocalyptic number.

It is an amenable number.

261351541 is a deficient number, since it is larger than the sum of its proper divisors (23759243).

261351541 is a wasteful number, since it uses less digits than its factorization.

261351541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23759242.

The product of its digits is 3600, while the sum is 28.

The square root of 261351541 is about 16166.3706811393. The cubic root of 261351541 is about 639.3544442741.

The spelling of 261351541 in words is "two hundred sixty-one million, three hundred fifty-one thousand, five hundred forty-one".