51387982 has 4 divisors (see below), whose sum is σ = 77081976. Its totient is φ = 25693990.

The previous prime is 51387961. The next prime is 51388019. The reversal of 51387982 is 28978315.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28978315 = 5 ⋅5795663.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12846994 + ... + 12846997.

It is an arithmetic number, because the mean of its divisors is an integer number (19270494).

Almost surely, 2^51387982 is an apocalyptic number.

51387982 is a deficient number, since it is larger than the sum of its proper divisors (25693994).

51387982 is a wasteful number, since it uses less digits than its factorization.

51387982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25693993.

The product of its digits is 120960, while the sum is 43.

The square root of 51387982 is about 7168.5411347080. The cubic root of 51387982 is about 371.7809970435.

The spelling of 51387982 in words is "fifty-one million, three hundred eighty-seven thousand, nine hundred eighty-two".