261125601 has 16 divisors (see below), whose sum is σ = 396334080. Its totient is φ = 151376720.

The previous prime is 261125587. The next prime is 261125603. The reversal of 261125601 is 106521162.

It is not a de Polignac number, because 261125601 - 2⁶ = 261125537 is a prime.

It is a super-2 number, since 2×261125601² = 136373158995222402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261125603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171261 + ... + 172778.

It is an arithmetic number, because the mean of its divisors is an integer number (24770880).

Almost surely, 2^261125601 is an apocalyptic number.

It is an amenable number.

261125601 is a deficient number, since it is larger than the sum of its proper divisors (135208479).

261125601 is a wasteful number, since it uses less digits than its factorization.

261125601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344076.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 261125601 is about 16159.3812072121. The cubic root of 261125601 is about 639.1701492180.

Adding to 261125601 its reverse (106521162), we get a palindrome (367646763).

It can be divided in two parts, 261125 and 601, that added together give a triangular number (261726 = T₇₂₃).

The spelling of 261125601 in words is "two hundred sixty-one million, one hundred twenty-five thousand, six hundred one".