87995981 has 2 divisors, whose sum is σ = 87995982. Its totient is φ = 87995980.

The previous prime is 87995867. The next prime is 87995989. The reversal of 87995981 is 18959978.

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., 68326756 + 19669225 = 8266^2 + 4435^2 .

It is a cyclic number.

It is not a de Polignac number, because 87995981 - 2¹⁴ = 87979597 is a prime.

It is a super-2 number, since 2×87995981² = 15486585344304722, 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 (87995989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43997990 + 43997991.

It is an arithmetic number, because the mean of its divisors is an integer number (43997991).

Almost surely, 2^87995981 is an apocalyptic number.

It is an amenable number.

87995981 is a deficient number, since it is larger than the sum of its proper divisors (1).

87995981 is an equidigital number, since it uses as much as digits as its factorization.

87995981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 56.

The square root of 87995981 is about 9380.6173037812. The cubic root of 87995981 is about 444.7892466653.

The spelling of 87995981 in words is "eighty-seven million, nine hundred ninety-five thousand, nine hundred eighty-one".