51001620 has 24 divisors (see below), whose sum is σ = 142804704. Its totient is φ = 13600416.

The previous prime is 51001619. The next prime is 51001729. The reversal of 51001620 is 2610015.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 51001620.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 424954 + ... + 425073.

It is an arithmetic number, because the mean of its divisors is an integer number (5950196).

Almost surely, 2^51001620 is an apocalyptic number.

It is an amenable number.

51001620 is an abundant number, since it is smaller than the sum of its proper divisors (91803084).

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

51001620 is a wasteful number, since it uses less digits than its factorization.

51001620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850039 (or 850037 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 51001620 is about 7141.5418503290. The cubic root of 51001620 is about 370.8469034577.

Adding to 51001620 its reverse (2610015), we get a palindrome (53611635).

The spelling of 51001620 in words is "fifty-one million, one thousand, six hundred twenty".