51479821 has 2 divisors, whose sum is σ = 51479822. Its totient is φ = 51479820.

The previous prime is 51479777. The next prime is 51479851. The reversal of 51479821 is 12897415.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38266596 + 13213225 = 6186^2 + 3635^2 .

It is a cyclic number.

It is not a de Polignac number, because 51479821 - 2⁷ = 51479693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51479851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25739910 + 25739911.

It is an arithmetic number, because the mean of its divisors is an integer number (25739911).

Almost surely, 2^51479821 is an apocalyptic number.

It is an amenable number.

51479821 is a deficient number, since it is larger than the sum of its proper divisors (1).

51479821 is an equidigital number, since it uses as much as digits as its factorization.

51479821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 51479821 is about 7174.9439719067. The cubic root of 51479821 is about 372.0023437051.

The spelling of 51479821 in words is "fifty-one million, four hundred seventy-nine thousand, eight hundred twenty-one".