51221087 has 2 divisors, whose sum is σ = 51221088. Its totient is φ = 51221086.

The previous prime is 51221081. The next prime is 51221101. The reversal of 51221087 is 78012215.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51221087 - 2¹⁰ = 51220063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51221081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25610543 + 25610544.

It is an arithmetic number, because the mean of its divisors is an integer number (25610544).

Almost surely, 2^51221087 is an apocalyptic number.

51221087 is a deficient number, since it is larger than the sum of its proper divisors (1).

51221087 is an equidigital number, since it uses as much as digits as its factorization.

51221087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 51221087 is about 7156.8908752335. The cubic root of 51221087 is about 371.3780773920.

The spelling of 51221087 in words is "fifty-one million, two hundred twenty-one thousand, eighty-seven".