51863991 has 8 divisors (see below), whose sum is σ = 73219824. Its totient is φ = 32542080.

The previous prime is 51863971. The next prime is 51864013. The reversal of 51863991 is 19936815.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51863991 - 2⁹ = 51863479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51863971) 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, 508420 + ... + 508521.

It is an arithmetic number, because the mean of its divisors is an integer number (9152478).

Almost surely, 2^51863991 is an apocalyptic number.

51863991 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

51863991 is a deficient number, since it is larger than the sum of its proper divisors (21355833).

51863991 is a wasteful number, since it uses less digits than its factorization.

51863991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016961.

The product of its digits is 58320, while the sum is 42.

The square root of 51863991 is about 7201.6658489547. The cubic root of 51863991 is about 372.9254116083.

The spelling of 51863991 in words is "fifty-one million, eight hundred sixty-three thousand, nine hundred ninety-one".