51387998 has 4 divisors (see below), whose sum is σ = 77082000. Its totient is φ = 25693998.

The previous prime is 51387961. The next prime is 51388019. The reversal of 51387998 is 89978315.

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

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, 12846998 + ... + 12847001.

It is an arithmetic number, because the mean of its divisors is an integer number (19270500).

Almost surely, 2^51387998 is an apocalyptic number.

51387998 is a deficient number, since it is larger than the sum of its proper divisors (25694002).

51387998 is a wasteful number, since it uses less digits than its factorization.

51387998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25694001.

The product of its digits is 544320, while the sum is 50.

The square root of 51387998 is about 7168.5422506950. The cubic root of 51387998 is about 371.7810356290.

The spelling of 51387998 in words is "fifty-one million, three hundred eighty-seven thousand, nine hundred ninety-eight".