61221313 has 2 divisors, whose sum is σ = 61221314. Its totient is φ = 61221312.

The previous prime is 61221229. The next prime is 61221341. The reversal of 61221313 is 31312216.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45603009 + 15618304 = 6753^2 + 3952^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61221313 is a prime.

It is a super-3 number, since 3×61221313³ (a number of 24 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (61221343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30610656 + 30610657.

It is an arithmetic number, because the mean of its divisors is an integer number (30610657).

Almost surely, 2^61221313 is an apocalyptic number.

It is an amenable number.

61221313 is a deficient number, since it is larger than the sum of its proper divisors (1).

61221313 is an equidigital number, since it uses as much as digits as its factorization.

61221313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 61221313 is about 7824.4049614012. The cubic root of 61221313 is about 394.1252082157.

Adding to 61221313 its reverse (31312216), we get a palindrome (92533529).

The spelling of 61221313 in words is "sixty-one million, two hundred twenty-one thousand, three hundred thirteen".