261221380223 has 4 divisors (see below), whose sum is σ = 261248261808. Its totient is φ = 261194498640.

The previous prime is 261221380213. The next prime is 261221380267. The reversal of 261221380223 is 322083122162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 322083122162 = 2 ⋅161041561081.

It is a cyclic number.

It is not a de Polignac number, because 261221380223 - 2⁶ = 261221380159 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261221380223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261221380213) 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, 13426211 + ... + 13445652.

It is an arithmetic number, because the mean of its divisors is an integer number (65312065452).

Almost surely, 2^261221380223 is an apocalyptic number.

261221380223 is a deficient number, since it is larger than the sum of its proper divisors (26881585).

261221380223 is an equidigital number, since it uses as much as digits as its factorization.

261221380223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26881584.

The product of its (nonzero) digits is 13824, while the sum is 32.

The spelling of 261221380223 in words is "two hundred sixty-one billion, two hundred twenty-one million, three hundred eighty thousand, two hundred twenty-three".