51151381 has 4 divisors (see below), whose sum is σ = 52340992. Its totient is φ = 49961772.

The previous prime is 51151357. The next prime is 51151403. The reversal of 51151381 is 18315115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51151381 is a prime.

It is a super-2 number, since 2×51151381² = 5232927556414322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51151981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 594741 + ... + 594826.

It is an arithmetic number, because the mean of its divisors is an integer number (13085248).

Almost surely, 2^51151381 is an apocalyptic number.

It is an amenable number.

51151381 is a deficient number, since it is larger than the sum of its proper divisors (1189611).

51151381 is a wasteful number, since it uses less digits than its factorization.

51151381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1189610.

The product of its digits is 600, while the sum is 25.

The square root of 51151381 is about 7152.0193651863. The cubic root of 51151381 is about 371.2095333159.

Adding to 51151381 its reverse (18315115), we get a palindrome (69466496).

The spelling of 51151381 in words is "fifty-one million, one hundred fifty-one thousand, three hundred eighty-one".