51640845 has 16 divisors (see below), whose sum is σ = 83136192. Its totient is φ = 27371520.

The previous prime is 51640843. The next prime is 51640847. The reversal of 51640845 is 54804615.

It is an interprime number because it is at equal distance from previous prime (51640843) and next prime (51640847).

It is not a de Polignac number, because 51640845 - 2¹ = 51640843 is a prime.

It is a super-3 number, since 3×51640845³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51640843) 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, 8116 + ... + 13005.

It is an arithmetic number, because the mean of its divisors is an integer number (5196012).

Almost surely, 2^51640845 is an apocalyptic number.

It is an amenable number.

51640845 is a deficient number, since it is larger than the sum of its proper divisors (31495347).

51640845 is a wasteful number, since it uses less digits than its factorization.

51640845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21292.

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 51640845 is about 7186.1564831278. The cubic root of 51640845 is about 372.3898026961.

The spelling of 51640845 in words is "fifty-one million, six hundred forty thousand, eight hundred forty-five".