51506647 has 4 divisors (see below), whose sum is σ = 52704520. Its totient is φ = 50308776.

The previous prime is 51506633. The next prime is 51506659. The reversal of 51506647 is 74660515.

It is a happy number.

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 51506647 - 2¹⁵ = 51473879 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 (51506677) 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, 598872 + ... + 598957.

It is an arithmetic number, because the mean of its divisors is an integer number (13176130).

Almost surely, 2^51506647 is an apocalyptic number.

51506647 is a deficient number, since it is larger than the sum of its proper divisors (1197873).

51506647 is a wasteful number, since it uses less digits than its factorization.

51506647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1197872.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 51506647 is about 7176.8131506958. The cubic root of 51506647 is about 372.0669489671.

The spelling of 51506647 in words is "fifty-one million, five hundred six thousand, six hundred forty-seven".