51540894381 has 4 divisors (see below), whose sum is σ = 68721192512. Its totient is φ = 34360596252.

The previous prime is 51540894359. The next prime is 51540894403. The reversal of 51540894381 is 18349804515.

It is a happy number.

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 an interprime number because it is at equal distance from previous prime (51540894359) and next prime (51540894403).

It is not a de Polignac number, because 51540894381 - 2¹⁸ = 51540632237 is a prime.

It is a super-2 number, since 2×51540894381² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51540894381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51540894311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8590149061 + ... + 8590149066.

It is an arithmetic number, because the mean of its divisors is an integer number (17180298128).

Almost surely, 2^51540894381 is an apocalyptic number.

It is an amenable number.

51540894381 is a deficient number, since it is larger than the sum of its proper divisors (17180298131).

51540894381 is a wasteful number, since it uses less digits than its factorization.

51540894381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17180298130.

The product of its (nonzero) digits is 691200, while the sum is 48.

The spelling of 51540894381 in words is "fifty-one billion, five hundred forty million, eight hundred ninety-four thousand, three hundred eighty-one".