261612207 has 16 divisors (see below), whose sum is σ = 391932000. Its totient is φ = 172446912.

The previous prime is 261612203. The next prime is 261612233. The reversal of 261612207 is 702216162.

261612207 is a `hidden beast` number, since 26 + 1 + 612 + 20 + 7 = 666.

It is not a de Polignac number, because 261612207 - 2² = 261612203 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261612203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52032 + ... + 56837.

It is an arithmetic number, because the mean of its divisors is an integer number (24495750).

Almost surely, 2^261612207 is an apocalyptic number.

261612207 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

261612207 is a deficient number, since it is larger than the sum of its proper divisors (130319793).

261612207 is a wasteful number, since it uses less digits than its factorization.

261612207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108967 (or 108961 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 261612207 is about 16174.4306545857. The cubic root of 261612207 is about 639.5669327723.

Adding to 261612207 its reverse (702216162), we get a palindrome (963828369).

The spelling of 261612207 in words is "two hundred sixty-one million, six hundred twelve thousand, two hundred seven".