261619221 has 8 divisors (see below), whose sum is σ = 348900480. Its totient is φ = 174375392.

The previous prime is 261619219. The next prime is 261619223. The reversal of 261619221 is 122916162.

It is an interprime number because it is at equal distance from previous prime (261619219) and next prime (261619223).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261619221 - 2¹ = 261619219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261619223) 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 7 ways as a sum of consecutive naturals, for example, 21385 + ... + 31313.

It is an arithmetic number, because the mean of its divisors is an integer number (43612560).

Almost surely, 2^261619221 is an apocalyptic number.

It is an amenable number.

261619221 is a deficient number, since it is larger than the sum of its proper divisors (87281259).

261619221 is an equidigital number, since it uses as much as digits as its factorization.

261619221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18715.

The product of its digits is 2592, while the sum is 30.

The square root of 261619221 is about 16174.6474768386. The cubic root of 261619221 is about 639.5726484617.

The spelling of 261619221 in words is "two hundred sixty-one million, six hundred nineteen thousand, two hundred twenty-one".