87814921 has 2 divisors, whose sum is σ = 87814922. Its totient is φ = 87814920.

The previous prime is 87814891. The next prime is 87814931. The reversal of 87814921 is 12941878.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70476025 + 17338896 = 8395^2 + 4164^2 .

It is a cyclic number.

It is not a de Polignac number, because 87814921 - 2⁵ = 87814889 is a prime.

It is a super-2 number, since 2×87814921² = 15422920700472482, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (87814931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43907460 + 43907461.

It is an arithmetic number, because the mean of its divisors is an integer number (43907461).

Almost surely, 2^87814921 is an apocalyptic number.

It is an amenable number.

87814921 is a deficient number, since it is larger than the sum of its proper divisors (1).

87814921 is an equidigital number, since it uses as much as digits as its factorization.

87814921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 40.

The square root of 87814921 is about 9370.9615835303. The cubic root of 87814921 is about 444.4839719682.

The spelling of 87814921 in words is "eighty-seven million, eight hundred fourteen thousand, nine hundred twenty-one".