51846721 has 2 divisors, whose sum is σ = 51846722. Its totient is φ = 51846720.

The previous prime is 51846713. The next prime is 51846727. The reversal of 51846721 is 12764815.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38626225 + 13220496 = 6215^2 + 3636^2 .

It is a cyclic number.

It is not a de Polignac number, because 51846721 - 2³ = 51846713 is a prime.

It is a super-3 number, since 3×51846721³ (a number of 24 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (51846727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25923360 + 25923361.

It is an arithmetic number, because the mean of its divisors is an integer number (25923361).

Almost surely, 2^51846721 is an apocalyptic number.

It is an amenable number.

51846721 is a deficient number, since it is larger than the sum of its proper divisors (1).

51846721 is an equidigital number, since it uses as much as digits as its factorization.

51846721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 34.

The square root of 51846721 is about 7200.4667209841. The cubic root of 51846721 is about 372.8840139916.

The spelling of 51846721 in words is "fifty-one million, eight hundred forty-six thousand, seven hundred twenty-one".