51891555 has 8 divisors (see below), whose sum is σ = 83026512. Its totient is φ = 27675488.

The previous prime is 51891533. The next prime is 51891569. The reversal of 51891555 is 55519815.

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 51891555 - 2⁶ = 51891491 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1729704 + ... + 1729733.

It is an arithmetic number, because the mean of its divisors is an integer number (10378314).

Almost surely, 2^51891555 is an apocalyptic number.

51891555 is a deficient number, since it is larger than the sum of its proper divisors (31134957).

51891555 is a wasteful number, since it uses less digits than its factorization.

51891555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3459445.

The product of its digits is 45000, while the sum is 39.

The square root of 51891555 is about 7203.5793186443. The cubic root of 51891555 is about 372.9914657584.

The spelling of 51891555 in words is "fifty-one million, eight hundred ninety-one thousand, five hundred fifty-five".