51408869 has 4 divisors (see below), whose sum is σ = 51880620. Its totient is φ = 50937120.

The previous prime is 51408829. The next prime is 51408871. The reversal of 51408869 is 96880415.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12496225 + 38912644 = 3535^2 + 6238^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51408869 is a prime.

It is a super-2 number, since 2×51408869² = 5285743623718322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51408829) 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, 235712 + ... + 235929.

It is an arithmetic number, because the mean of its divisors is an integer number (12970155).

Almost surely, 2^51408869 is an apocalyptic number.

It is an amenable number.

51408869 is a deficient number, since it is larger than the sum of its proper divisors (471751).

51408869 is a wasteful number, since it uses less digits than its factorization.

51408869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471750.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 51408869 is about 7169.9978382145. The cubic root of 51408869 is about 371.8313612046.

The spelling of 51408869 in words is "fifty-one million, four hundred eight thousand, eight hundred sixty-nine".