61609717 has 16 divisors (see below), whose sum is σ = 72681840. Its totient is φ = 51674112.

The previous prime is 61609703. The next prime is 61609721. The reversal of 61609717 is 71790616.

It can be written as a sum of positive squares in 8 ways, for example, as 6345361 + 55264356 = 2519^2 + 7434^2 .

It is a 5-Lehmer number, since φ(61609717) divides (61609717-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 61609717 - 2⁷ = 61609589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61609727) 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, 1603 + ... + 11215.

It is an arithmetic number, because the mean of its divisors is an integer number (4542615).

Almost surely, 2^61609717 is an apocalyptic number.

61609717 is the 6409-th pentagonal number.

It is an amenable number.

61609717 is a deficient number, since it is larger than the sum of its proper divisors (11072123).

61609717 is a wasteful number, since it uses less digits than its factorization.

61609717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9672.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 61609717 is about 7849.1857539493. The cubic root of 61609717 is about 394.9569295558.

It can be divided in two parts, 61609 and 717, that added together give a palindrome (62326).

The spelling of 61609717 in words is "sixty-one million, six hundred nine thousand, seven hundred seventeen".