51687887 has 4 divisors (see below), whose sum is σ = 52459416. Its totient is φ = 50916360.

The previous prime is 51687863. The next prime is 51687899. The reversal of 51687887 is 78878615.

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

It is a cyclic number.

It is not a de Polignac number, because 51687887 - 2¹⁰ = 51686863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51687817) 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, 385664 + ... + 385797.

It is an arithmetic number, because the mean of its divisors is an integer number (13114854).

Almost surely, 2^51687887 is an apocalyptic number.

51687887 is a deficient number, since it is larger than the sum of its proper divisors (771529).

51687887 is an equidigital number, since it uses as much as digits as its factorization.

51687887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771528.

The product of its digits is 752640, while the sum is 50.

The square root of 51687887 is about 7189.4288368409. The cubic root of 51687887 is about 372.5028439943.

It can be divided in two parts, 516878 and 87, that multiplied together give a triangular number (44968386 = T₉₄₈₃).

The spelling of 51687887 in words is "fifty-one million, six hundred eighty-seven thousand, eight hundred eighty-seven".