51866413 has 4 divisors (see below), whose sum is σ = 53654940. Its totient is φ = 50077888.

The previous prime is 51866407. The next prime is 51866417. The reversal of 51866413 is 31466815.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31466815 = 5 ⋅6293363.

It can be written as a sum of positive squares in 2 ways, for example, as 30503529 + 21362884 = 5523^2 + 4622^2 .

It is a cyclic number.

It is not a de Polignac number, because 51866413 - 2⁹ = 51865901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51866417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 894220 + ... + 894277.

It is an arithmetic number, because the mean of its divisors is an integer number (13413735).

Almost surely, 2^51866413 is an apocalyptic number.

It is an amenable number.

51866413 is a deficient number, since it is larger than the sum of its proper divisors (1788527).

51866413 is a wasteful number, since it uses less digits than its factorization.

51866413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788526.

The product of its digits is 17280, while the sum is 34.

The square root of 51866413 is about 7201.8340025302. The cubic root of 51866413 is about 372.9312166075.

The spelling of 51866413 in words is "fifty-one million, eight hundred sixty-six thousand, four hundred thirteen".