166561428 has 24 divisors (see below), whose sum is σ = 423974880. Its totient is φ = 50473120.

The previous prime is 166561411. The next prime is 166561433. The reversal of 166561428 is 824165661.

It is a happy number.

166561428 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 630783 + ... + 631046.

It is an arithmetic number, because the mean of its divisors is an integer number (17665620).

Almost surely, 2^166561428 is an apocalyptic number.

It is an amenable number.

166561428 is an abundant number, since it is smaller than the sum of its proper divisors (257413452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166561428 is a wasteful number, since it uses less digits than its factorization.

166561428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261847 (or 1261845 counting only the distinct ones).

The product of its digits is 69120, while the sum is 39.

The square root of 166561428 is about 12905.8679677114. The cubic root of 166561428 is about 550.2053536206.

The spelling of 166561428 in words is "one hundred sixty-six million, five hundred sixty-one thousand, four hundred twenty-eight".