51031420261 has 2 divisors, whose sum is σ = 51031420262. Its totient is φ = 51031420260.

The previous prime is 51031420241. The next prime is 51031420273. The reversal of 51031420261 is 16202413015.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32418002500 + 18613417761 = 180050^2 + 136431^2 .

It is a cyclic number.

It is not a de Polignac number, because 51031420261 - 2⁹ = 51031419749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51031420241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25515710130 + 25515710131.

It is an arithmetic number, because the mean of its divisors is an integer number (25515710131).

Almost surely, 2^51031420261 is an apocalyptic number.

It is an amenable number.

51031420261 is a deficient number, since it is larger than the sum of its proper divisors (1).

51031420261 is an equidigital number, since it uses as much as digits as its factorization.

51031420261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 51031420261 its reverse (16202413015), we get a palindrome (67233833276).

The spelling of 51031420261 in words is "fifty-one billion, thirty-one million, four hundred twenty thousand, two hundred sixty-one".