61665100253 has 2 divisors, whose sum is σ = 61665100254. Its totient is φ = 61665100252.

The previous prime is 61665100181. The next prime is 61665100271. The reversal of 61665100253 is 35200156616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59358987769 + 2306112484 = 243637^2 + 48022^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61665100253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61665100753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30832550126 + 30832550127.

It is an arithmetic number, because the mean of its divisors is an integer number (30832550127).

Almost surely, 2^61665100253 is an apocalyptic number.

It is an amenable number.

61665100253 is a deficient number, since it is larger than the sum of its proper divisors (1).

61665100253 is an equidigital number, since it uses as much as digits as its factorization.

61665100253 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 35.

Adding to 61665100253 its reverse (35200156616), we get a palindrome (96865256869).

The spelling of 61665100253 in words is "sixty-one billion, six hundred sixty-five million, one hundred thousand, two hundred fifty-three".