61661613 has 32 divisors (see below), whose sum is σ = 91897344. Its totient is φ = 36533952.

The previous prime is 61661539. The next prime is 61661617. The reversal of 61661613 is 31616616.

It is not a de Polignac number, because 61661613 - 2⁸ = 61661357 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61661617) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138970 + ... + 139412.

It is an arithmetic number, because the mean of its divisors is an integer number (2871792).

Almost surely, 2^61661613 is an apocalyptic number.

It is an amenable number.

61661613 is a deficient number, since it is larger than the sum of its proper divisors (30235731).

61661613 is a wasteful number, since it uses less digits than its factorization.

61661613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585.

The product of its digits is 3888, while the sum is 30.

The square root of 61661613 is about 7852.4908786958. The cubic root of 61661613 is about 395.0677937370.

The spelling of 61661613 in words is "sixty-one million, six hundred sixty-one thousand, six hundred thirteen".