51378820 has 12 divisors (see below), whose sum is σ = 107895564. Its totient is φ = 20551520.

The previous prime is 51378799. The next prime is 51378823. The reversal of 51378820 is 2887315.

It can be written as a sum of positive squares in 2 ways, for example, as 31002624 + 20376196 = 5568^2 + 4514^2 .

It is not an unprimeable number, because it can be changed into a prime (51378823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1284451 + ... + 1284490.

It is an arithmetic number, because the mean of its divisors is an integer number (8991297).

Almost surely, 2^51378820 is an apocalyptic number.

It is an amenable number.

51378820 is an abundant number, since it is smaller than the sum of its proper divisors (56516744).

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

51378820 is a wasteful number, since it uses less digits than its factorization.

51378820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2568950 (or 2568948 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 51378820 is about 7167.9020640631. The cubic root of 51378820 is about 371.7589006971.

The spelling of 51378820 in words is "fifty-one million, three hundred seventy-eight thousand, eight hundred twenty".