261221380227 has 12 divisors (see below), whose sum is σ = 377647605504. Its totient is φ = 173996278800.

The previous prime is 261221380213. The next prime is 261221380267. The reversal of 261221380227 is 722083122162.

261221380227 is a `hidden beast` number, since 2 + 612 + 2 + 1 + 38 + 0 + 2 + 2 + 7 = 666.

It is not a de Polignac number, because 261221380227 - 2¹⁶ = 261221314691 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261221380191 and 261221380200.

It is not an unprimeable number, because it can be changed into a prime (261221380267) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12598068 + ... + 12618785.

It is an arithmetic number, because the mean of its divisors is an integer number (31470633792).

Almost surely, 2^261221380227 is an apocalyptic number.

261221380227 is a deficient number, since it is larger than the sum of its proper divisors (116426225277).

261221380227 is a wasteful number, since it uses less digits than its factorization.

261221380227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25218010 (or 25218007 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 261221380227 in words is "two hundred sixty-one billion, two hundred twenty-one million, three hundred eighty thousand, two hundred twenty-seven".