51660645 has 32 divisors (see below), whose sum is σ = 86959872. Its totient is φ = 26138112.

The previous prime is 51660641. The next prime is 51660649. The reversal of 51660645 is 54606615.

It is an interprime number because it is at equal distance from previous prime (51660641) and next prime (51660649).

It is not a de Polignac number, because 51660645 - 2² = 51660641 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51660641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46719 + ... + 47811.

It is an arithmetic number, because the mean of its divisors is an integer number (2717496).

Almost surely, 2^51660645 is an apocalyptic number.

It is an amenable number.

51660645 is a deficient number, since it is larger than the sum of its proper divisors (35299227).

51660645 is a wasteful number, since it uses less digits than its factorization.

51660645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 51660645 is about 7187.5339999196. The cubic root of 51660645 is about 372.4373901948.

The spelling of 51660645 in words is "fifty-one million, six hundred sixty thousand, six hundred forty-five".