261220051 has 8 divisors (see below), whose sum is σ = 265391360. Its totient is φ = 257080392.

The previous prime is 261220021. The next prime is 261220121. The reversal of 261220051 is 150022162.

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 261220051 - 2⁵ = 261220019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261220021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9010 + ... + 24568.

It is an arithmetic number, because the mean of its divisors is an integer number (33173920).

Almost surely, 2^261220051 is an apocalyptic number.

261220051 is a deficient number, since it is larger than the sum of its proper divisors (4171309).

261220051 is a wasteful number, since it uses less digits than its factorization.

261220051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15825.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 261220051 is about 16162.3033940092. The cubic root of 261220051 is about 639.2472032527.

The spelling of 261220051 in words is "two hundred sixty-one million, two hundred twenty thousand, fifty-one".