51523212421 has 2 divisors, whose sum is σ = 51523212422. Its totient is φ = 51523212420.

The previous prime is 51523212407. The next prime is 51523212439. The reversal of 51523212421 is 12421232515.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50386780900 + 1136431521 = 224470^2 + 33711^2 .

It is a cyclic number.

It is not a de Polignac number, because 51523212421 - 2¹⁷ = 51523081349 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51523212421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51523212721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25761606210 + 25761606211.

It is an arithmetic number, because the mean of its divisors is an integer number (25761606211).

Almost surely, 2^51523212421 is an apocalyptic number.

It is an amenable number.

51523212421 is a deficient number, since it is larger than the sum of its proper divisors (1).

51523212421 is an equidigital number, since it uses as much as digits as its factorization.

51523212421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4800, while the sum is 28.

Adding to 51523212421 its reverse (12421232515), we get a palindrome (63944444936).

The spelling of 51523212421 in words is "fifty-one billion, five hundred twenty-three million, two hundred twelve thousand, four hundred twenty-one".