51855000 has 80 divisors (see below), whose sum is σ = 162041880. Its totient is φ = 13824000.

The previous prime is 51854963. The next prime is 51855007. The reversal of 51855000 is 55815.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51855007) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13272 + ... + 16728.

Almost surely, 2^51855000 is an apocalyptic number.

51855000 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51855000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81020940).

51855000 is an abundant number, since it is smaller than the sum of its proper divisors (110186880).

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

51855000 is a wasteful number, since it uses less digits than its factorization.

51855000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3486 (or 3467 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 24.

The square root of 51855000 is about 7201.0415913255. The cubic root of 51855000 is about 372.9038605855.

The spelling of 51855000 in words is "fifty-one million, eight hundred fifty-five thousand".