51221550 has 24 divisors (see below), whose sum is σ = 127029816. Its totient is φ = 13659040.

The previous prime is 51221543. The next prime is 51221563. The reversal of 51221550 is 5512215.

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 11 ways as a sum of consecutive naturals, for example, 170589 + ... + 170888.

It is an arithmetic number, because the mean of its divisors is an integer number (5292909).

Almost surely, 2^51221550 is an apocalyptic number.

51221550 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

51221550 is an abundant number, since it is smaller than the sum of its proper divisors (75808266).

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

51221550 is a wasteful number, since it uses less digits than its factorization.

51221550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341492 (or 341487 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 51221550 is about 7156.9232216086. The cubic root of 51221550 is about 371.3791963812.

Adding to 51221550 its reverse (5512215), we get a palindrome (56733765).

The spelling of 51221550 in words is "fifty-one million, two hundred twenty-one thousand, five hundred fifty".