61601209 has 2 divisors, whose sum is σ = 61601210. Its totient is φ = 61601208.

The previous prime is 61601201. The next prime is 61601227. The reversal of 61601209 is 90210616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46172025 + 15429184 = 6795^2 + 3928^2 .

It is a cyclic number.

It is not a de Polignac number, because 61601209 - 2³ = 61601201 is a prime.

It is not a weakly prime, because it can be changed into another prime (61601201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30800604 + 30800605.

It is an arithmetic number, because the mean of its divisors is an integer number (30800605).

Almost surely, 2^61601209 is an apocalyptic number.

It is an amenable number.

61601209 is a deficient number, since it is larger than the sum of its proper divisors (1).

61601209 is an equidigital number, since it uses as much as digits as its factorization.

61601209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 61601209 is about 7848.6437681933. The cubic root of 61601209 is about 394.9387481800.

The spelling of 61601209 in words is "sixty-one million, six hundred one thousand, two hundred nine".