61636321 has 2 divisors, whose sum is σ = 61636322. Its totient is φ = 61636320.

The previous prime is 61636319. The next prime is 61636357. The reversal of 61636321 is 12363616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53290000 + 8346321 = 7300^2 + 2889^2 .

It is a cyclic number.

It is not a de Polignac number, because 61636321 - 2¹ = 61636319 is a prime.

Together with 61636319, it forms a pair of twin primes.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 61636321.

It is not a weakly prime, because it can be changed into another prime (61636301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30818160 + 30818161.

It is an arithmetic number, because the mean of its divisors is an integer number (30818161).

Almost surely, 2^61636321 is an apocalyptic number.

It is an amenable number.

61636321 is a deficient number, since it is larger than the sum of its proper divisors (1).

61636321 is an equidigital number, since it uses as much as digits as its factorization.

61636321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 28.

The square root of 61636321 is about 7850.8802691163. The cubic root of 61636321 is about 395.0137708172.

Adding to 61636321 its reverse (12363616), we get a palindrome (73999937).

The spelling of 61636321 in words is "sixty-one million, six hundred thirty-six thousand, three hundred twenty-one".