51211220 has 24 divisors (see below), whose sum is σ = 107793504. Its totient is φ = 20436896.

The previous prime is 51211217. The next prime is 51211231. The reversal of 51211220 is 2211215.

It is a junction number, because it is equal to n+sod(n) for n = 51211195 and 51211204.

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, 6599 + ... + 12081.

It is an arithmetic number, because the mean of its divisors is an integer number (4491396).

Almost surely, 2^51211220 is an apocalyptic number.

It is an amenable number.

51211220 is an abundant number, since it is smaller than the sum of its proper divisors (56582284).

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

51211220 is a wasteful number, since it uses less digits than its factorization.

51211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5959 (or 5957 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 51211220 is about 7156.2015063859. The cubic root of 51211220 is about 371.3542289927.

Adding to 51211220 its reverse (2211215), we get a palindrome (53422435).

The spelling of 51211220 in words is "fifty-one million, two hundred eleven thousand, two hundred twenty".