51687369 has 16 divisors (see below), whose sum is σ = 76861440. Its totient is φ = 34328880.

The previous prime is 51687359. The next prime is 51687379. The reversal of 51687369 is 96378615.

It is a happy number.

51687369 is a `hidden beast` number, since 516 + 8 + 73 + 69 = 666.

It is an interprime number because it is at equal distance from previous prime (51687359) and next prime (51687379).

It is not a de Polignac number, because 51687369 - 2⁷ = 51687241 is a prime.

It is a super-2 number, since 2×51687369² = 5343168228284322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51687329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4024 + ... + 10934.

It is an arithmetic number, because the mean of its divisors is an integer number (4803840).

Almost surely, 2^51687369 is an apocalyptic number.

It is an amenable number.

51687369 is a deficient number, since it is larger than the sum of its proper divisors (25174071).

51687369 is a wasteful number, since it uses less digits than its factorization.

51687369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7197 (or 7191 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 51687369 is about 7189.3928116358. The cubic root of 51687369 is about 372.5015996208.

The spelling of 51687369 in words is "fifty-one million, six hundred eighty-seven thousand, three hundred sixty-nine".