61606721 has 16 divisors (see below), whose sum is σ = 71064000. Its totient is φ = 52819200.

The previous prime is 61606717. The next prime is 61606729. The reversal of 61606721 is 12760616.

It is a cyclic number.

It is not a de Polignac number, because 61606721 - 2² = 61606717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61606729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58205 + ... + 59253.

It is an arithmetic number, because the mean of its divisors is an integer number (4441500).

Almost surely, 2^61606721 is an apocalyptic number.

It is an amenable number.

61606721 is a deficient number, since it is larger than the sum of its proper divisors (9457279).

61606721 is a wasteful number, since it uses less digits than its factorization.

61606721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 61606721 is about 7848.9949038077. The cubic root of 61606721 is about 394.9505273723.

The spelling of 61606721 in words is "sixty-one million, six hundred six thousand, seven hundred twenty-one".