261136641 has 16 divisors (see below), whose sum is σ = 366664320. Its totient is φ = 164989440.

The previous prime is 261136637. The next prime is 261136657. The reversal of 261136641 is 146631162.

It is not a de Polignac number, because 261136641 - 2² = 261136637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261136599 and 261136608.

It is not an unprimeable number, because it can be changed into a prime (261136661) 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, 9840 + ... + 24881.

It is an arithmetic number, because the mean of its divisors is an integer number (22916520).

Almost surely, 2^261136641 is an apocalyptic number.

It is an amenable number.

261136641 is a deficient number, since it is larger than the sum of its proper divisors (105527679).

261136641 is a wasteful number, since it uses less digits than its factorization.

261136641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34856.

The product of its digits is 5184, while the sum is 30.

The square root of 261136641 is about 16159.7228008404. The cubic root of 261136641 is about 639.1791568104.

The spelling of 261136641 in words is "two hundred sixty-one million, one hundred thirty-six thousand, six hundred forty-one".