51209850 has 48 divisors (see below), whose sum is σ = 130447008. Its totient is φ = 13285440.

The previous prime is 51209843. The next prime is 51209863. The reversal of 51209850 is 5890215.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 937 + ... + 10163.

It is an arithmetic number, because the mean of its divisors is an integer number (2717646).

Almost surely, 2^51209850 is an apocalyptic number.

51209850 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 51209850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65223504).

51209850 is an abundant number, since it is smaller than the sum of its proper divisors (79237158).

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

51209850 is a wasteful number, since it uses less digits than its factorization.

51209850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9279 (or 9274 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 51209850 is about 7156.1057845731. The cubic root of 51209850 is about 371.3509174799.

The spelling of 51209850 in words is "fifty-one million, two hundred nine thousand, eight hundred fifty".