51381887 has 2 divisors, whose sum is σ = 51381888. Its totient is φ = 51381886.

The previous prime is 51381829. The next prime is 51381901. The reversal of 51381887 is 78818315.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51381887 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51381817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25690943 + 25690944.

It is an arithmetic number, because the mean of its divisors is an integer number (25690944).

Almost surely, 2^51381887 is an apocalyptic number.

51381887 is a deficient number, since it is larger than the sum of its proper divisors (1).

51381887 is an equidigital number, since it uses as much as digits as its factorization.

51381887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 41.

The square root of 51381887 is about 7168.1160007355. The cubic root of 51381887 is about 371.7662977909.

It can be divided in two parts, 5138 and 1887, that multiplied together give a triangular number (9695406 = T₄₄₀₃).

The spelling of 51381887 in words is "fifty-one million, three hundred eighty-one thousand, eight hundred eighty-seven".