51487947 has 16 divisors (see below), whose sum is σ = 87175680. Its totient is φ = 29421576.

The previous prime is 51487939. The next prime is 51487981. The reversal of 51487947 is 74978415.

It is a happy number.

It is not a de Polignac number, because 51487947 - 2³ = 51487939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51487907) 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, 136023 + ... + 136400.

It is an arithmetic number, because the mean of its divisors is an integer number (5448480).

Almost surely, 2^51487947 is an apocalyptic number.

51487947 is a deficient number, since it is larger than the sum of its proper divisors (35687733).

51487947 is a wasteful number, since it uses less digits than its factorization.

51487947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272439 (or 272433 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 51487947 is about 7175.5102257610. The cubic root of 51487947 is about 372.0219159825.

The spelling of 51487947 in words is "fifty-one million, four hundred eighty-seven thousand, nine hundred forty-seven".