51221545 has 8 divisors (see below), whose sum is σ = 62308296. Its totient is φ = 40415616.

The previous prime is 51221543. The next prime is 51221563. The reversal of 51221545 is 54512215.

It can be written as a sum of positive squares in 4 ways, for example, as 484416 + 50737129 = 696^2 + 7123^2 .

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 51221545 - 2¹ = 51221543 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51221543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69802 + ... + 70531.

It is an arithmetic number, because the mean of its divisors is an integer number (7788537).

Almost surely, 2^51221545 is an apocalyptic number.

It is an amenable number.

51221545 is a deficient number, since it is larger than the sum of its proper divisors (11086751).

51221545 is a wasteful number, since it uses less digits than its factorization.

51221545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140411.

The product of its digits is 2000, while the sum is 25.

The square root of 51221545 is about 7156.9228722964. The cubic root of 51221545 is about 371.3791842971.

The spelling of 51221545 in words is "fifty-one million, two hundred twenty-one thousand, five hundred forty-five".