261220153 has 2 divisors, whose sum is σ = 261220154. Its totient is φ = 261220152.

The previous prime is 261220123. The next prime is 261220187. The reversal of 261220153 is 351022162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 215414329 + 45805824 = 14677^2 + 6768^2 .

It is a cyclic number.

It is not a de Polignac number, because 261220153 - 2⁵ = 261220121 is a prime.

It is not a weakly prime, because it can be changed into another prime (261220123) 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 as a sum of consecutive naturals, namely, 130610076 + 130610077.

It is an arithmetic number, because the mean of its divisors is an integer number (130610077).

Almost surely, 2^261220153 is an apocalyptic number.

It is an amenable number.

261220153 is a deficient number, since it is larger than the sum of its proper divisors (1).

261220153 is an equidigital number, since it uses as much as digits as its factorization.

261220153 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 261220153 is about 16162.3065494997. The cubic root of 261220153 is about 639.2472864562.

The spelling of 261220153 in words is "two hundred sixty-one million, two hundred twenty thousand, one hundred fifty-three".