51991248 has 20 divisors (see below), whose sum is σ = 134310848. Its totient is φ = 17330400.

The previous prime is 51991231. The next prime is 51991249. The reversal of 51991248 is 84219915.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51991249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541528 + ... + 541623.

Almost surely, 2^51991248 is an apocalyptic number.

It is an amenable number.

51991248 is an abundant number, since it is smaller than the sum of its proper divisors (82319600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51991248 is a wasteful number, since it uses less digits than its factorization.

51991248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083162 (or 1083156 counting only the distinct ones).

The product of its digits is 25920, while the sum is 39.

The square root of 51991248 is about 7210.4956833771. The cubic root of 51991248 is about 373.2301741622.

The spelling of 51991248 in words is "fifty-one million, nine hundred ninety-one thousand, two hundred forty-eight".