166561442 has 8 divisors (see below), whose sum is σ = 258457500. Its totient is φ = 80408944.

The previous prime is 166561441. The next prime is 166561463. The reversal of 166561442 is 244165661.

166561442 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 166384201 + 177241 = 12899^2 + 421^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×166561442² = 55485427922238728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166561441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1435817 + ... + 1435932.

Almost surely, 2^166561442 is an apocalyptic number.

166561442 is a deficient number, since it is larger than the sum of its proper divisors (91896058).

166561442 is a wasteful number, since it uses less digits than its factorization.

166561442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2871780.

The product of its digits is 34560, while the sum is 35.

The square root of 166561442 is about 12905.8685101004. The cubic root of 166561442 is about 550.2053690360.

The spelling of 166561442 in words is "one hundred sixty-six million, five hundred sixty-one thousand, four hundred forty-two".