51023220 has 24 divisors (see below), whose sum is σ = 142865184. Its totient is φ = 13606176.

The previous prime is 51023207. The next prime is 51023221. The reversal of 51023220 is 2232015.

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 51023220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51023221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 425134 + ... + 425253.

It is an arithmetic number, because the mean of its divisors is an integer number (5952716).

Almost surely, 2^51023220 is an apocalyptic number.

It is an amenable number.

51023220 is an abundant number, since it is smaller than the sum of its proper divisors (91841964).

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

51023220 is a wasteful number, since it uses less digits than its factorization.

51023220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850399 (or 850397 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 51023220 is about 7143.0539687167. The cubic root of 51023220 is about 370.8992492627.

Adding to 51023220 its reverse (2232015), we get a palindrome (53255235).

The spelling of 51023220 in words is "fifty-one million, twenty-three thousand, two hundred twenty".