51321858 has 64 divisors (see below), whose sum is σ = 120960000. Its totient is φ = 14215104.

The previous prime is 51321857. The next prime is 51321859. The reversal of 51321858 is 85812315.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51321857) and next prime (51321859).

It is not an unprimeable number, because it can be changed into a prime (51321857) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 344368 + ... + 344516.

It is an arithmetic number, because the mean of its divisors is an integer number (1890000).

Almost surely, 2^51321858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51321858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60480000).

51321858 is an abundant number, since it is smaller than the sum of its proper divisors (69638142).

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

51321858 is a wasteful number, since it uses less digits than its factorization.

51321858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359.

The product of its digits is 9600, while the sum is 33.

The square root of 51321858 is about 7163.9275540726. The cubic root of 51321858 is about 371.6214642912.

The spelling of 51321858 in words is "fifty-one million, three hundred twenty-one thousand, eight hundred fifty-eight".