166240981 has 2 divisors, whose sum is σ = 166240982. Its totient is φ = 166240980.

The previous prime is 166240973. The next prime is 166240993. The reversal of 166240981 is 189042661.

It is a happy number.

166240981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134768881 + 31472100 = 11609^2 + 5610^2 .

It is a cyclic number.

It is not a de Polignac number, because 166240981 - 2³ = 166240973 is a prime.

It is a super-2 number, since 2×166240981² = 55272127527684722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 166240981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166240901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83120490 + 83120491.

It is an arithmetic number, because the mean of its divisors is an integer number (83120491).

Almost surely, 2^166240981 is an apocalyptic number.

It is an amenable number.

166240981 is a deficient number, since it is larger than the sum of its proper divisors (1).

166240981 is an equidigital number, since it uses as much as digits as its factorization.

166240981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 166240981 is about 12893.4472116653. The cubic root of 166240981 is about 549.8522809903.

The spelling of 166240981 in words is "one hundred sixty-six million, two hundred forty thousand, nine hundred eighty-one".