61645657 has 2 divisors, whose sum is σ = 61645658. Its totient is φ = 61645656.

The previous prime is 61645651. The next prime is 61645667. The reversal of 61645657 is 75654616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46090521 + 15555136 = 6789^2 + 3944^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61645657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61645651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30822828 + 30822829.

It is an arithmetic number, because the mean of its divisors is an integer number (30822829).

Almost surely, 2^61645657 is an apocalyptic number.

It is an amenable number.

61645657 is a deficient number, since it is larger than the sum of its proper divisors (1).

61645657 is an equidigital number, since it uses as much as digits as its factorization.

61645657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151200, while the sum is 40.

The square root of 61645657 is about 7851.4748296100. The cubic root of 61645657 is about 395.0337139413.

The spelling of 61645657 in words is "sixty-one million, six hundred forty-five thousand, six hundred fifty-seven".