261424421 has 4 divisors (see below), whose sum is σ = 261505344. Its totient is φ = 261343500.

The previous prime is 261424411. The next prime is 261424447. The reversal of 261424421 is 124424162.

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 a cyclic number.

It is not a de Polignac number, because 261424421 - 2¹⁰ = 261423397 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 (261424411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35405 + ... + 42146.

It is an arithmetic number, because the mean of its divisors is an integer number (65376336).

Almost surely, 2^261424421 is an apocalyptic number.

It is an amenable number.

261424421 is a deficient number, since it is larger than the sum of its proper divisors (80923).

261424421 is an equidigital number, since it uses as much as digits as its factorization.

261424421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80922.

The product of its digits is 3072, while the sum is 26.

The square root of 261424421 is about 16168.6245859071. The cubic root of 261424421 is about 639.4138684774.

Adding to 261424421 its reverse (124424162), we get a palindrome (385848583).

The spelling of 261424421 in words is "two hundred sixty-one million, four hundred twenty-four thousand, four hundred twenty-one".