51998993281 has 8 divisors (see below), whose sum is σ = 52070667264. Its totient is φ = 51927363600.

The previous prime is 51998993279. The next prime is 51998993317. The reversal of 51998993281 is 18239989915.

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 51998993281 - 2¹ = 51998993279 is a prime.

It is a super-3 number, since 3×51998993281³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51998993681) 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, 2814831 + ... + 2833243.

It is an arithmetic number, because the mean of its divisors is an integer number (6508833408).

Almost surely, 2^51998993281 is an apocalyptic number.

It is an amenable number.

51998993281 is a deficient number, since it is larger than the sum of its proper divisors (71673983).

51998993281 is a wasteful number, since it uses less digits than its factorization.

51998993281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22151.

The product of its digits is 12597120, while the sum is 64.

The spelling of 51998993281 in words is "fifty-one billion, nine hundred ninety-eight million, nine hundred ninety-three thousand, two hundred eighty-one".