51445890 has 96 divisors (see below), whose sum is σ = 138692736. Its totient is φ = 13224960.

The previous prime is 51445847. The next prime is 51445903. The reversal of 51445890 is 9854415.

51445890 is a `hidden beast` number, since 514 + 4 + 58 + 90 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 530322 + ... + 530418.

It is an arithmetic number, because the mean of its divisors is an integer number (1444716).

Almost surely, 2^51445890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51445890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69346368).

51445890 is an abundant number, since it is smaller than the sum of its proper divisors (87246846).

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

51445890 is a wasteful number, since it uses less digits than its factorization.

51445890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 51445890 is about 7172.5790340714. The cubic root of 51445890 is about 371.9205952615.

The spelling of 51445890 in words is "fifty-one million, four hundred forty-five thousand, eight hundred ninety".