51147878 has 4 divisors (see below), whose sum is σ = 76721820. Its totient is φ = 25573938.

The previous prime is 51147847. The next prime is 51147893. The reversal of 51147878 is 87874115.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×51147878² = 5232210847805768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12786968 + ... + 12786971.

It is an arithmetic number, because the mean of its divisors is an integer number (19180455).

Almost surely, 2^51147878 is an apocalyptic number.

51147878 is a deficient number, since it is larger than the sum of its proper divisors (25573942).

51147878 is a wasteful number, since it uses less digits than its factorization.

51147878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25573941.

The product of its digits is 62720, while the sum is 41.

The square root of 51147878 is about 7151.7744651240. The cubic root of 51147878 is about 371.2010592751.

It can be divided in two parts, 51147 and 878, that added together give a palindrome (52025).

The spelling of 51147878 in words is "fifty-one million, one hundred forty-seven thousand, eight hundred seventy-eight".