51816945 has 16 divisors (see below), whose sum is σ = 83099520. Its totient is φ = 27571584.

The previous prime is 51816943. The next prime is 51816959. The reversal of 51816945 is 54961815.

It is not a de Polignac number, because 51816945 - 2¹ = 51816943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51816943) 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, 3076 + ... + 10634.

It is an arithmetic number, because the mean of its divisors is an integer number (5193720).

Almost surely, 2^51816945 is an apocalyptic number.

It is an amenable number.

51816945 is a deficient number, since it is larger than the sum of its proper divisors (31282575).

51816945 is a wasteful number, since it uses less digits than its factorization.

51816945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8024.

The product of its digits is 43200, while the sum is 39.

The square root of 51816945 is about 7198.3987802844. The cubic root of 51816945 is about 372.8126168658.

The spelling of 51816945 in words is "fifty-one million, eight hundred sixteen thousand, nine hundred forty-five".