51904820 has 48 divisors (see below), whose sum is σ = 119883456. Its totient is φ = 18720000.

The previous prime is 51904807. The next prime is 51904829. The reversal of 51904820 is 2840915.

It is a super-2 number, since 2×51904820² = 5388220678464800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51904829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27920 + ... + 29720.

It is an arithmetic number, because the mean of its divisors is an integer number (2497572).

Almost surely, 2^51904820 is an apocalyptic number.

It is a pronic number, being equal to 7204×7205.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51904820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59941728).

51904820 is an abundant number, since it is smaller than the sum of its proper divisors (67978636).

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

51904820 is a wasteful number, since it uses less digits than its factorization.

51904820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1952 (or 1950 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 51904820 is about 7204.4999826497. The cubic root of 51904820 is about 373.0232455619.

The spelling of 51904820 in words is "fifty-one million, nine hundred four thousand, eight hundred twenty".