61656813 has 24 divisors (see below), whose sum is σ = 96145920. Its totient is φ = 37957920.

The previous prime is 61656781. The next prime is 61656821. The reversal of 61656813 is 31865616.

It is a happy number.

It is not a de Polignac number, because 61656813 - 2⁵ = 61656781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61656823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 868 + ... + 11138.

It is an arithmetic number, because the mean of its divisors is an integer number (4006080).

Almost surely, 2^61656813 is an apocalyptic number.

It is an amenable number.

61656813 is a deficient number, since it is larger than the sum of its proper divisors (34489107).

61656813 is a wasteful number, since it uses less digits than its factorization.

61656813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10329 (or 10326 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 61656813 is about 7852.1852372445. The cubic root of 61656813 is about 395.0575422232.

The spelling of 61656813 in words is "sixty-one million, six hundred fifty-six thousand, eight hundred thirteen".