55129857 has 8 divisors (see below), whose sum is σ = 73608384. Its totient is φ = 36702288.

The previous prime is 55129843. The next prime is 55129903. The reversal of 55129857 is 75892155.

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

It is not a de Polignac number, because 55129857 - 2¹⁵ = 55097089 is a prime.

It is a super-2 number, since 2×55129857² = 6078602265680898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55129807) 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 7 ways as a sum of consecutive naturals, for example, 10138 + ... + 14595.

It is an arithmetic number, because the mean of its divisors is an integer number (9201048).

Almost surely, 2^55129857 is an apocalyptic number.

It is an amenable number.

55129857 is a deficient number, since it is larger than the sum of its proper divisors (18478527).

55129857 is a wasteful number, since it uses less digits than its factorization.

55129857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25479.

The product of its digits is 126000, while the sum is 42.

The square root of 55129857 is about 7424.9482826482. The cubic root of 55129857 is about 380.5943078026.

The spelling of 55129857 in words is "fifty-five million, one hundred twenty-nine thousand, eight hundred fifty-seven".