51621211 has 4 divisors (see below), whose sum is σ = 51638872. Its totient is φ = 51603552.

The previous prime is 51621209. The next prime is 51621217. The reversal of 51621211 is 11212615.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51621211 - 2¹ = 51621209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51621217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3285 + ... + 10678.

It is an arithmetic number, because the mean of its divisors is an integer number (12909718).

Almost surely, 2^51621211 is an apocalyptic number.

51621211 is a deficient number, since it is larger than the sum of its proper divisors (17661).

51621211 is a wasteful number, since it uses less digits than its factorization.

51621211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17660.

The product of its digits is 120, while the sum is 19.

The square root of 51621211 is about 7184.7902544194. The cubic root of 51621211 is about 372.3426021503.

Adding to 51621211 its reverse (11212615), we get a palindrome (62833826).

The spelling of 51621211 in words is "fifty-one million, six hundred twenty-one thousand, two hundred eleven".