51388121 has 2 divisors, whose sum is σ = 51388122. Its totient is φ = 51388120.

The previous prime is 51388091. The next prime is 51388147. The reversal of 51388121 is 12188315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50410000 + 978121 = 7100^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 51388121 - 2¹⁰ = 51387097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51388151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25694060 + 25694061.

It is an arithmetic number, because the mean of its divisors is an integer number (25694061).

Almost surely, 2^51388121 is an apocalyptic number.

It is an amenable number.

51388121 is a deficient number, since it is larger than the sum of its proper divisors (1).

51388121 is an equidigital number, since it uses as much as digits as its factorization.

51388121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 29.

The square root of 51388121 is about 7168.5508298400. The cubic root of 51388121 is about 371.7813322548.

The spelling of 51388121 in words is "fifty-one million, three hundred eighty-eight thousand, one hundred twenty-one".