61689609 has 6 divisors (see below), whose sum is σ = 89107226. Its totient is φ = 41126400.

The previous prime is 61689587. The next prime is 61689629. The reversal of 61689609 is 90698616.

It can be written as a sum of positive squares in only one way, i.e., 52707600 + 8982009 = 7260^2 + 2997^2 .

It is not a de Polignac number, because 61689609 - 2⁹ = 61689097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61689629) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3427192 + ... + 3427209.

Almost surely, 2^61689609 is an apocalyptic number.

It is an amenable number.

61689609 is a deficient number, since it is larger than the sum of its proper divisors (27417617).

61689609 is a wasteful number, since it uses less digits than its factorization.

61689609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6854407 (or 6854404 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 61689609 is about 7854.2732954743. The cubic root of 61689609 is about 395.1275750928.

The spelling of 61689609 in words is "sixty-one million, six hundred eighty-nine thousand, six hundred nine".