261101131 has 2 divisors, whose sum is σ = 261101132. Its totient is φ = 261101130.

The previous prime is 261101063. The next prime is 261101143. The reversal of 261101131 is 131101162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261101131 - 2¹⁹ = 260576843 is a prime.

It is a super-2 number, since 2×261101131² = 136347601218958322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (261101531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130550565 + 130550566.

It is an arithmetic number, because the mean of its divisors is an integer number (130550566).

Almost surely, 2^261101131 is an apocalyptic number.

261101131 is a deficient number, since it is larger than the sum of its proper divisors (1).

261101131 is an equidigital number, since it uses as much as digits as its factorization.

261101131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 261101131 is about 16158.6240441444. The cubic root of 261101131 is about 639.1501831147.

Adding to 261101131 its reverse (131101162), we get a palindrome (392202293).

The spelling of 261101131 in words is "two hundred sixty-one million, one hundred one thousand, one hundred thirty-one".