51481138 has 4 divisors (see below), whose sum is σ = 77221710. Its totient is φ = 25740568.

The previous prime is 51481093. The next prime is 51481141. The reversal of 51481138 is 83118415.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83118415 = 5 ⋅16623683.

It can be written as a sum of positive squares in only one way, i.e., 49885969 + 1595169 = 7063^2 + 1263^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12870283 + ... + 12870286.

Almost surely, 2^51481138 is an apocalyptic number.

51481138 is a deficient number, since it is larger than the sum of its proper divisors (25740572).

51481138 is a wasteful number, since it uses less digits than its factorization.

51481138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25740571.

The product of its digits is 3840, while the sum is 31.

The square root of 51481138 is about 7175.0357490399. The cubic root of 51481138 is about 372.0055159702.

The spelling of 51481138 in words is "fifty-one million, four hundred eighty-one thousand, one hundred thirty-eight".