75661261 has 16 divisors (see below), whose sum is σ = 85201200. Its totient is φ = 66705408.

The previous prime is 75661259. The next prime is 75661273. The reversal of 75661261 is 16216657.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 11356900 + 64304361 = 3370^2 + 8019^2 .

It is a cyclic number.

It is not a de Polignac number, because 75661261 - 2¹ = 75661259 is a prime.

It is a super-2 number, since 2×75661261² = 11449252832220242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75661231) 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, 35535 + ... + 37603.

It is an arithmetic number, because the mean of its divisors is an integer number (5325075).

Almost surely, 2^75661261 is an apocalyptic number.

It is an amenable number.

75661261 is a deficient number, since it is larger than the sum of its proper divisors (9539939).

75661261 is a wasteful number, since it uses less digits than its factorization.

75661261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2208.

The product of its digits is 15120, while the sum is 34.

The square root of 75661261 is about 8698.3481765218. The cubic root of 75661261 is about 422.9521059363.

The spelling of 75661261 in words is "seventy-five million, six hundred sixty-one thousand, two hundred sixty-one".