51212261 has 2 divisors, whose sum is σ = 51212262. Its totient is φ = 51212260.

The previous prime is 51212221. The next prime is 51212263. The reversal of 51212261 is 16221215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42837025 + 8375236 = 6545^2 + 2894^2 .

It is a cyclic number.

It is not a de Polignac number, because 51212261 - 2⁶ = 51212197 is a prime.

Together with 51212263, it forms a pair of twin primes.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 51212261 parts by 10120 straight cuts.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51212263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25606130 + 25606131.

It is an arithmetic number, because the mean of its divisors is an integer number (25606131).

Almost surely, 2^51212261 is an apocalyptic number.

It is an amenable number.

51212261 is a deficient number, since it is larger than the sum of its proper divisors (1).

51212261 is an equidigital number, since it uses as much as digits as its factorization.

51212261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 20.

The square root of 51212261 is about 7156.2742401336. The cubic root of 51212261 is about 371.3567452195.

Adding to 51212261 its reverse (16221215), we get a palindrome (67433476).

The spelling of 51212261 in words is "fifty-one million, two hundred twelve thousand, two hundred sixty-one".