51143989 has 4 divisors (see below), whose sum is σ = 55078156. Its totient is φ = 47209824.

The previous prime is 51143987. The next prime is 51144013. The reversal of 51143989 is 98934115.

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 30140100 + 21003889 = 5490^2 + 4583^2 .

It is a cyclic number.

It is not a de Polignac number, because 51143989 - 2¹ = 51143987 is a prime.

It is a super-3 number, since 3×51143989³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51143987) 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, 1967064 + ... + 1967089.

It is an arithmetic number, because the mean of its divisors is an integer number (13769539).

Almost surely, 2^51143989 is an apocalyptic number.

It is an amenable number.

51143989 is a deficient number, since it is larger than the sum of its proper divisors (3934167).

51143989 is a wasteful number, since it uses less digits than its factorization.

51143989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3934166.

The product of its digits is 38880, while the sum is 40.

The square root of 51143989 is about 7151.5025693906. The cubic root of 51143989 is about 371.1916510157.

The spelling of 51143989 in words is "fifty-one million, one hundred forty-three thousand, nine hundred eighty-nine".