51621329 has 2 divisors, whose sum is σ = 51621330. Its totient is φ = 51621328.

The previous prime is 51621319. The next prime is 51621341. The reversal of 51621329 is 92312615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49730704 + 1890625 = 7052^2 + 1375^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51621329 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51621319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25810664 + 25810665.

It is an arithmetic number, because the mean of its divisors is an integer number (25810665).

Almost surely, 2^51621329 is an apocalyptic number.

It is an amenable number.

51621329 is a deficient number, since it is larger than the sum of its proper divisors (1).

51621329 is an equidigital number, since it uses as much as digits as its factorization.

51621329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 29.

The square root of 51621329 is about 7184.7984662063. The cubic root of 51621329 is about 372.3428858605.

The spelling of 51621329 in words is "fifty-one million, six hundred twenty-one thousand, three hundred twenty-nine".