51621521 has 8 divisors (see below), whose sum is σ = 59062080. Its totient is φ = 44197488.

The previous prime is 51621511. The next prime is 51621527. The reversal of 51621521 is 12512615.

It is a happy number.

51621521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51621521 - 2¹⁰ = 51620497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51621527) 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 in 7 ways as a sum of consecutive naturals, for example, 3515 + ... + 10751.

It is an arithmetic number, because the mean of its divisors is an integer number (7382760).

Almost surely, 2^51621521 is an apocalyptic number.

It is an amenable number.

51621521 is a deficient number, since it is larger than the sum of its proper divisors (7440559).

51621521 is a wasteful number, since it uses less digits than its factorization.

51621521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8263.

The product of its digits is 600, while the sum is 23.

The square root of 51621521 is about 7184.8118277377. The cubic root of 51621521 is about 372.3433474898.

The spelling of 51621521 in words is "fifty-one million, six hundred twenty-one thousand, five hundred twenty-one".