51521401 has 2 divisors, whose sum is σ = 51521402. Its totient is φ = 51521400.

The previous prime is 51521399. The next prime is 51521423. The reversal of 51521401 is 10412515.

51521401 = 5075² + 5076².

51521401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25765776 + 25755625 = 5076^2 + 5075^2 .

It is a cyclic number.

It is not a de Polignac number, because 51521401 - 2¹ = 51521399 is a prime.

It is a super-2 number, since 2×51521401² = 5308909522005602, which contains 22 as substring.

Together with 51521399, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51521471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25760700 + 25760701.

It is an arithmetic number, because the mean of its divisors is an integer number (25760701).

Almost surely, 2^51521401 is an apocalyptic number.

51521401 is the 5076-th centered square number.

It is an amenable number.

51521401 is a deficient number, since it is larger than the sum of its proper divisors (1).

51521401 is an equidigital number, since it uses as much as digits as its factorization.

51521401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 51521401 is about 7177.8409706541. The cubic root of 51521401 is about 372.1024715778.

Adding to 51521401 its reverse (10412515), we get a palindrome (61933916).

The spelling of 51521401 in words is "fifty-one million, five hundred twenty-one thousand, four hundred one".