261061001 has 2 divisors, whose sum is σ = 261061002. Its totient is φ = 261061000.

The previous prime is 261060997. The next prime is 261061039. The reversal of 261061001 is 100160162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228010000 + 33051001 = 15100^2 + 5749^2 .

It is a cyclic number.

It is not a de Polignac number, because 261061001 - 2² = 261060997 is a prime.

It is not a weakly prime, because it can be changed into another prime (261061091) 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, 130530500 + 130530501.

It is an arithmetic number, because the mean of its divisors is an integer number (130530501).

Almost surely, 2^261061001 is an apocalyptic number.

It is an amenable number.

261061001 is a deficient number, since it is larger than the sum of its proper divisors (1).

261061001 is an equidigital number, since it uses as much as digits as its factorization.

261061001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 261061001 is about 16157.3822446583. The cubic root of 261061001 is about 639.1174366575.

The spelling of 261061001 in words is "two hundred sixty-one million, sixty-one thousand, one".