87219901 has 2 divisors, whose sum is σ = 87219902. Its totient is φ = 87219900.

The previous prime is 87219893. The next prime is 87219929. The reversal of 87219901 is 10991278.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77616100 + 9603801 = 8810^2 + 3099^2 .

It is a cyclic number.

It is not a de Polignac number, because 87219901 - 2³ = 87219893 is a prime.

It is a super-2 number, since 2×87219901² = 15214622260899602, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87219961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43609950 + 43609951.

It is an arithmetic number, because the mean of its divisors is an integer number (43609951).

Almost surely, 2^87219901 is an apocalyptic number.

It is an amenable number.

87219901 is a deficient number, since it is larger than the sum of its proper divisors (1).

87219901 is an equidigital number, since it uses as much as digits as its factorization.

87219901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 87219901 is about 9339.1595446271. The cubic root of 87219901 is about 443.4777782602.

The spelling of 87219901 in words is "eighty-seven million, two hundred nineteen thousand, nine hundred one".