51356647 has 4 divisors (see below), whose sum is σ = 51374736. Its totient is φ = 51338560.

The previous prime is 51356633. The next prime is 51356687. The reversal of 51356647 is 74665315.

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 51356647 - 2¹⁹ = 50832359 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 (51356687) 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, 3754 + ... + 10807.

It is an arithmetic number, because the mean of its divisors is an integer number (12843684).

Almost surely, 2^51356647 is an apocalyptic number.

51356647 is a deficient number, since it is larger than the sum of its proper divisors (18089).

51356647 is a wasteful number, since it uses less digits than its factorization.

51356647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18088.

The product of its digits is 75600, while the sum is 37.

The square root of 51356647 is about 7166.3552102865. The cubic root of 51356647 is about 371.7054143502.

It can be divided in two parts, 51356 and 647, that added together give a triangular number (52003 = T₃₂₂).

The spelling of 51356647 in words is "fifty-one million, three hundred fifty-six thousand, six hundred forty-seven".