51115878 has 24 divisors (see below), whose sum is σ = 120819816. Its totient is φ = 15489600.

The previous prime is 51115873. The next prime is 51115879. The reversal of 51115878 is 87851115.

It is a happy number.

It is a super-2 number, since 2×51115878² = 5225665967421768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51115873) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 128883 + ... + 129278.

It is an arithmetic number, because the mean of its divisors is an integer number (5034159).

Almost surely, 2^51115878 is an apocalyptic number.

51115878 is an abundant number, since it is smaller than the sum of its proper divisors (69703938).

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

51115878 is a wasteful number, since it uses less digits than its factorization.

51115878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258180 (or 258177 counting only the distinct ones).

The product of its digits is 11200, while the sum is 36.

The square root of 51115878 is about 7149.5369080801. The cubic root of 51115878 is about 371.1236307650.

The spelling of 51115878 in words is "fifty-one million, one hundred fifteen thousand, eight hundred seventy-eight".