51820019 has 8 divisors (see below), whose sum is σ = 52647168. Its totient is φ = 50999040.

The previous prime is 51820009. The next prime is 51820037. The reversal of 51820019 is 91002815.

It is a happy number.

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 51820019 - 2²⁰ = 50771443 is a prime.

It is a super-2 number, since 2×51820019² = 5370628738320722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51820019.

It is not an unprimeable number, because it can be changed into a prime (51820009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17129 + ... + 19925.

It is an arithmetic number, because the mean of its divisors is an integer number (6580896).

Almost surely, 2^51820019 is an apocalyptic number.

51820019 is a deficient number, since it is larger than the sum of its proper divisors (827149).

51820019 is a wasteful number, since it uses less digits than its factorization.

51820019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3085.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 51820019 is about 7198.6122968250. The cubic root of 51820019 is about 372.8199889929.

The spelling of 51820019 in words is "fifty-one million, eight hundred twenty thousand, nineteen".