51821571 has 16 divisors (see below), whose sum is σ = 71709344. Its totient is φ = 33260544.

The previous prime is 51821557. The next prime is 51821587. The reversal of 51821571 is 17512815.

It is not a de Polignac number, because 51821571 - 2⁷ = 51821443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51821591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8361 + ... + 13173.

It is an arithmetic number, because the mean of its divisors is an integer number (4481834).

Almost surely, 2^51821571 is an apocalyptic number.

51821571 is a deficient number, since it is larger than the sum of its proper divisors (19887773).

51821571 is a wasteful number, since it uses less digits than its factorization.

51821571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4950.

The product of its digits is 2800, while the sum is 30.

The square root of 51821571 is about 7198.7200945724. The cubic root of 51821571 is about 372.8237109191.

The spelling of 51821571 in words is "fifty-one million, eight hundred twenty-one thousand, five hundred seventy-one".