61805857 has 2 divisors, whose sum is σ = 61805858. Its totient is φ = 61805856.

The previous prime is 61805833. The next prime is 61805869. The reversal of 61805857 is 75850816.

61805857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31764496 + 30041361 = 5636^2 + 5481^2 .

It is a cyclic number.

It is not a de Polignac number, because 61805857 - 2¹⁹ = 61281569 is a prime.

It is not a weakly prime, because it can be changed into another prime (61805057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30902928 + 30902929.

It is an arithmetic number, because the mean of its divisors is an integer number (30902929).

Almost surely, 2^61805857 is an apocalyptic number.

It is an amenable number.

61805857 is a deficient number, since it is larger than the sum of its proper divisors (1).

61805857 is an equidigital number, since it uses as much as digits as its factorization.

61805857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 67200, while the sum is 40.

The square root of 61805857 is about 7861.6701151854. The cubic root of 61805857 is about 395.3756123734.

The spelling of 61805857 in words is "sixty-one million, eight hundred five thousand, eight hundred fifty-seven".