61129685 has 4 divisors (see below), whose sum is σ = 73355628. Its totient is φ = 48903744.

The previous prime is 61129681. The next prime is 61129687. The reversal of 61129685 is 58692116.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9778129 + 51351556 = 3127^2 + 7166^2 .

It is a cyclic number.

It is not a de Polignac number, because 61129685 - 2² = 61129681 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 (61129681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6112964 + ... + 6112973.

It is an arithmetic number, because the mean of its divisors is an integer number (18338907).

Almost surely, 2^61129685 is an apocalyptic number.

It is an amenable number.

61129685 is a deficient number, since it is larger than the sum of its proper divisors (12225943).

61129685 is a wasteful number, since it uses less digits than its factorization.

61129685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12225942.

The product of its digits is 25920, while the sum is 38.

The square root of 61129685 is about 7818.5474993761. The cubic root of 61129685 is about 393.9284851348.

The spelling of 61129685 in words is "sixty-one million, one hundred twenty-nine thousand, six hundred eighty-five".