261221652251 has 8 divisors (see below), whose sum is σ = 305820471264. Its totient is φ = 218443193280.

The previous prime is 261221652193. The next prime is 261221652253. The reversal of 261221652251 is 152256122162.

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 261221652251 - 2³⁴ = 244041783067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261221652253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 455089700 + ... + 455090273.

It is an arithmetic number, because the mean of its divisors is an integer number (38227558908).

Almost surely, 2^261221652251 is an apocalyptic number.

261221652251 is a deficient number, since it is larger than the sum of its proper divisors (44598819013).

261221652251 is an equidigital number, since it uses as much as digits as its factorization.

261221652251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910180021.

The product of its digits is 28800, while the sum is 35.

The spelling of 261221652251 in words is "two hundred sixty-one billion, two hundred twenty-one million, six hundred fifty-two thousand, two hundred fifty-one".