87758221 has 2 divisors, whose sum is σ = 87758222. Its totient is φ = 87758220.

The previous prime is 87758219. The next prime is 87758249. The reversal of 87758221 is 12285778.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83814025 + 3944196 = 9155^2 + 1986^2 .

It is a cyclic number.

It is not a de Polignac number, because 87758221 - 2¹ = 87758219 is a prime.

Together with 87758219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87758521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43879110 + 43879111.

It is an arithmetic number, because the mean of its divisors is an integer number (43879111).

Almost surely, 2^87758221 is an apocalyptic number.

It is an amenable number.

87758221 is a deficient number, since it is larger than the sum of its proper divisors (1).

87758221 is an equidigital number, since it uses as much as digits as its factorization.

87758221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62720, while the sum is 40.

The square root of 87758221 is about 9367.9357918380. The cubic root of 87758221 is about 444.3882871384.

The spelling of 87758221 in words is "eighty-seven million, seven hundred fifty-eight thousand, two hundred twenty-one".