51621311 has 16 divisors (see below), whose sum is σ = 61121088. Its totient is φ = 42681600.

The previous prime is 51621307. The next prime is 51621319. The reversal of 51621311 is 11312615.

It is a cyclic number.

It is not a de Polignac number, because 51621311 - 2² = 51621307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51621319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21491 + ... + 23771.

It is an arithmetic number, because the mean of its divisors is an integer number (3820068).

Almost surely, 2^51621311 is an apocalyptic number.

51621311 is a deficient number, since it is larger than the sum of its proper divisors (9499777).

51621311 is a wasteful number, since it uses less digits than its factorization.

51621311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2402.

The product of its digits is 180, while the sum is 20.

The square root of 51621311 is about 7184.7972135614. The cubic root of 51621311 is about 372.3428425827.

Adding to 51621311 its reverse (11312615), we get a palindrome (62933926).

The spelling of 51621311 in words is "fifty-one million, six hundred twenty-one thousand, three hundred eleven".