51211553 has 2 divisors, whose sum is σ = 51211554. Its totient is φ = 51211552.

The previous prime is 51211543. The next prime is 51211571. The reversal of 51211553 is 35511215.

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., 51093904 + 117649 = 7148^2 + 343^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51211553 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51211543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25605776 + 25605777.

It is an arithmetic number, because the mean of its divisors is an integer number (25605777).

Almost surely, 2^51211553 is an apocalyptic number.

It is an amenable number.

51211553 is a deficient number, since it is larger than the sum of its proper divisors (1).

51211553 is an equidigital number, since it uses as much as digits as its factorization.

51211553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 750, while the sum is 23.

The square root of 51211553 is about 7156.2247728813. The cubic root of 51211553 is about 371.3550338989.

Adding to 51211553 its reverse (35511215), we get a palindrome (86722768).

The spelling of 51211553 in words is "fifty-one million, two hundred eleven thousand, five hundred fifty-three".