61809725 has 6 divisors (see below), whose sum is σ = 76644090. Its totient is φ = 49447760.

The previous prime is 61809703. The next prime is 61809731. The reversal of 61809725 is 52790816.

It can be written as a sum of positive squares in 3 ways, for example, as 17480761 + 44328964 = 4181^2 + 6658^2 .

It is not a de Polignac number, because 61809725 - 2¹⁰ = 61808701 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1236170 + ... + 1236219.

It is an arithmetic number, because the mean of its divisors is an integer number (12774015).

Almost surely, 2^61809725 is an apocalyptic number.

It is an amenable number.

61809725 is a deficient number, since it is larger than the sum of its proper divisors (14834365).

61809725 is a wasteful number, since it uses less digits than its factorization.

61809725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2472399 (or 2472394 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 61809725 is about 7861.9161150447. The cubic root of 61809725 is about 395.3838601407.

The spelling of 61809725 in words is "sixty-one million, eight hundred nine thousand, seven hundred twenty-five".