51511557 has 8 divisors (see below), whose sum is σ = 68717376. Its totient is φ = 34323392.

The previous prime is 51511541. The next prime is 51511561. The reversal of 51511557 is 75511515.

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 51511557 - 2⁴ = 51511541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51511517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5728 + ... + 11654.

It is an arithmetic number, because the mean of its divisors is an integer number (8589672).

Almost surely, 2^51511557 is an apocalyptic number.

It is an amenable number.

51511557 is a deficient number, since it is larger than the sum of its proper divisors (17205819).

51511557 is a wasteful number, since it uses less digits than its factorization.

51511557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8827.

The product of its digits is 4375, while the sum is 30.

The square root of 51511557 is about 7177.1552163793. The cubic root of 51511557 is about 372.0787713291.

The spelling of 51511557 in words is "fifty-one million, five hundred eleven thousand, five hundred fifty-seven".