51805413 has 24 divisors (see below), whose sum is σ = 84660576. Its totient is φ = 31395600.

The previous prime is 51805393. The next prime is 51805417. The reversal of 51805413 is 31450815.

It is not a de Polignac number, because 51805413 - 2⁶ = 51805349 is a prime.

It is a super-2 number, since 2×51805413² = 5367601632201138, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51805417) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7018 + ... + 12363.

It is an arithmetic number, because the mean of its divisors is an integer number (3527524).

Almost surely, 2^51805413 is an apocalyptic number.

It is an amenable number.

51805413 is a deficient number, since it is larger than the sum of its proper divisors (32855163).

51805413 is a wasteful number, since it uses less digits than its factorization.

51805413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19407 (or 19395 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 51805413 is about 7197.5977242411. The cubic root of 51805413 is about 372.7849579981.

The spelling of 51805413 in words is "fifty-one million, eight hundred five thousand, four hundred thirteen".