51785220 has 24 divisors (see below), whose sum is σ = 144998784. Its totient is φ = 13809376.

The previous prime is 51785219. The next prime is 51785267. The reversal of 51785220 is 2258715.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 431484 + ... + 431603.

It is an arithmetic number, because the mean of its divisors is an integer number (6041616).

Almost surely, 2^51785220 is an apocalyptic number.

It is an amenable number.

51785220 is an abundant number, since it is smaller than the sum of its proper divisors (93213564).

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

51785220 is a wasteful number, since it uses less digits than its factorization.

51785220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 863099 (or 863097 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 51785220 is about 7196.1948278239. The cubic root of 51785220 is about 372.7365163103.

The spelling of 51785220 in words is "fifty-one million, seven hundred eighty-five thousand, two hundred twenty".