61544210251 has 2 divisors, whose sum is σ = 61544210252. Its totient is φ = 61544210250.

The previous prime is 61544210249. The next prime is 61544210311. The reversal of 61544210251 is 15201244516.

It is a happy number.

61544210251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61544210251 - 2¹ = 61544210249 is a prime.

Together with 61544210249, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (61541210251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30772105125 + 30772105126.

It is an arithmetic number, because the mean of its divisors is an integer number (30772105126).

Almost surely, 2^61544210251 is an apocalyptic number.

61544210251 is a deficient number, since it is larger than the sum of its proper divisors (1).

61544210251 is an equidigital number, since it uses as much as digits as its factorization.

61544210251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 61544210251 its reverse (15201244516), we get a palindrome (76745454767).

The spelling of 61544210251 in words is "sixty-one billion, five hundred forty-four million, two hundred ten thousand, two hundred fifty-one".