51521100 has 72 divisors (see below), whose sum is σ = 149990400. Its totient is φ = 13654080.

The previous prime is 51521089. The next prime is 51521111. The reversal of 51521100 is 112515.

It is an interprime number because it is at equal distance from previous prime (51521089) and next prime (51521111).

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 51521100.

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, 59269 + ... + 60131.

It is an arithmetic number, because the mean of its divisors is an integer number (2083200).

Almost surely, 2^51521100 is an apocalyptic number.

51521100 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 51521100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74995200).

51521100 is an abundant number, since it is smaller than the sum of its proper divisors (98469300).

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

51521100 is a wasteful number, since it uses less digits than its factorization.

51521100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079 (or 1072 counting only the distinct ones).

The product of its (nonzero) digits is 50, while the sum is 15.

The square root of 51521100 is about 7177.8200033158. The cubic root of 51521100 is about 372.1017469400.

Adding to 51521100 its reverse (112515), we get a palindrome (51633615).

The spelling of 51521100 in words is "fifty-one million, five hundred twenty-one thousand, one hundred".