87981281 has 2 divisors, whose sum is σ = 87981282. Its totient is φ = 87981280.

The previous prime is 87981269. The next prime is 87981287. The reversal of 87981281 is 18218978.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87142225 + 839056 = 9335^2 + 916^2 .

It is a cyclic number.

It is not a de Polignac number, because 87981281 - 2¹⁴ = 87964897 is a prime.

It is a super-2 number, since 2×87981281² = 15481411612801922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (87981287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43990640 + 43990641.

It is an arithmetic number, because the mean of its divisors is an integer number (43990641).

Almost surely, 2^87981281 is an apocalyptic number.

It is an amenable number.

87981281 is a deficient number, since it is larger than the sum of its proper divisors (1).

87981281 is an equidigital number, since it uses as much as digits as its factorization.

87981281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 44.

The square root of 87981281 is about 9379.8337405308. The cubic root of 87981281 is about 444.7644774809.

The spelling of 87981281 in words is "eighty-seven million, nine hundred eighty-one thousand, two hundred eighty-one".