61636261 has 2 divisors, whose sum is σ = 61636262. Its totient is φ = 61636260.

The previous prime is 61636249. The next prime is 61636279. The reversal of 61636261 is 16263616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50680161 + 10956100 = 7119^2 + 3310^2 .

It is a cyclic number.

It is not a de Polignac number, because 61636261 - 2⁵ = 61636229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61636231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30818130 + 30818131.

It is an arithmetic number, because the mean of its divisors is an integer number (30818131).

Almost surely, 2^61636261 is an apocalyptic number.

It is an amenable number.

61636261 is a deficient number, since it is larger than the sum of its proper divisors (1).

61636261 is an equidigital number, since it uses as much as digits as its factorization.

61636261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 31.

The square root of 61636261 is about 7850.8764478878. The cubic root of 61636261 is about 395.0136426415.

Adding to 61636261 its reverse (16263616), we get a palindrome (77899877).

The spelling of 61636261 in words is "sixty-one million, six hundred thirty-six thousand, two hundred sixty-one".