51521000 has 32 divisors (see below), whose sum is σ = 120561480. Its totient is φ = 20608000.

The previous prime is 51520981. The next prime is 51521017. The reversal of 51521000 is 12515.

It can be written as a sum of positive squares in 4 ways, for example, as 1705636 + 49815364 = 1306^2 + 7058^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24761 + ... + 26760.

Almost surely, 2^51521000 is an apocalyptic number.

51521000 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51521000 is an abundant number, since it is smaller than the sum of its proper divisors (69040480).

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

51521000 is a wasteful number, since it uses less digits than its factorization.

51521000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51542 (or 51528 counting only the distinct ones).

The product of its (nonzero) digits is 50, while the sum is 14.

The square root of 51521000 is about 7177.8130374091. The cubic root of 51521000 is about 372.1015061959.

Adding to 51521000 its reverse (12515), we get a palindrome (51533515).

The spelling of 51521000 in words is "fifty-one million, five hundred twenty-one thousand".