3987166681 has 2 divisors, whose sum is σ = 3987166682. Its totient is φ = 3987166680.

The previous prime is 3987166661. The next prime is 3987166741. The reversal of 3987166681 is 1866617893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2073891600 + 1913275081 = 45540^2 + 43741^2 .

It is a cyclic number.

It is not a de Polignac number, because 3987166681 - 2¹³ = 3987158489 is a prime.

It is a super-2 number, since 2×3987166681² = 31794996284153111522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (3987166661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1993583340 + 1993583341.

It is an arithmetic number, because the mean of its divisors is an integer number (1993583341).

Almost surely, 2^3987166681 is an apocalyptic number.

It is an amenable number.

3987166681 is a deficient number, since it is larger than the sum of its proper divisors (1).

3987166681 is an equidigital number, since it uses as much as digits as its factorization.

3987166681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 55.

The square root of 3987166681 is about 63144.0154013031. The cubic root of 3987166681 is about 1585.7015978605.

The spelling of 3987166681 in words is "three billion, nine hundred eighty-seven million, one hundred sixty-six thousand, six hundred eighty-one".