61815253 has 2 divisors, whose sum is σ = 61815254. Its totient is φ = 61815252.

The previous prime is 61815239. The next prime is 61815263. The reversal of 61815253 is 35251816.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47238129 + 14577124 = 6873^2 + 3818^2 .

It is a cyclic number.

It is not a de Polignac number, because 61815253 - 2⁹ = 61814741 is a prime.

It is a super-2 number, since 2×61815253² = 7642251006908018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61815263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30907626 + 30907627.

It is an arithmetic number, because the mean of its divisors is an integer number (30907627).

Almost surely, 2^61815253 is an apocalyptic number.

It is an amenable number.

61815253 is a deficient number, since it is larger than the sum of its proper divisors (1).

61815253 is an equidigital number, since it uses as much as digits as its factorization.

61815253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 31.

The square root of 61815253 is about 7862.2676754229. The cubic root of 61815253 is about 395.3956469419.

The spelling of 61815253 in words is "sixty-one million, eight hundred fifteen thousand, two hundred fifty-three".