51219989 has 8 divisors (see below), whose sum is σ = 52727808. Its totient is φ = 49729680.

The previous prime is 51219983. The next prime is 51220033. The reversal of 51219989 is 98991215.

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 51219989 - 2¹² = 51215893 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 (51219983) 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, 1679 + ... + 10259.

It is an arithmetic number, because the mean of its divisors is an integer number (6590976).

Almost surely, 2^51219989 is an apocalyptic number.

It is an amenable number.

51219989 is a deficient number, since it is larger than the sum of its proper divisors (1507819).

51219989 is a wasteful number, since it uses less digits than its factorization.

51219989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8755.

The product of its digits is 58320, while the sum is 44.

The square root of 51219989 is about 7156.8141655348. The cubic root of 51219989 is about 371.3754236930.

The spelling of 51219989 in words is "fifty-one million, two hundred nineteen thousand, nine hundred eighty-nine".