51398218 has 4 divisors (see below), whose sum is σ = 77097330. Its totient is φ = 25699108.

The previous prime is 51398209. The next prime is 51398219. The reversal of 51398218 is 81289315.

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

It can be written as a sum of positive squares in only one way, i.e., 51022449 + 375769 = 7143^2 + 613^2 .

It is not an unprimeable number, because it can be changed into a prime (51398219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12849553 + ... + 12849556.

Almost surely, 2^51398218 is an apocalyptic number.

51398218 is a deficient number, since it is larger than the sum of its proper divisors (25699112).

51398218 is a wasteful number, since it uses less digits than its factorization.

51398218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25699111.

The product of its digits is 17280, while the sum is 37.

The square root of 51398218 is about 7169.2550519562. The cubic root of 51398218 is about 371.8056804908.

The spelling of 51398218 in words is "fifty-one million, three hundred ninety-eight thousand, two hundred eighteen".