166520978 has 32 divisors (see below), whose sum is σ = 284135040. Its totient is φ = 72558720.

The previous prime is 166520971. The next prime is 166520993. The reversal of 166520978 is 879025661.

166520978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×166520978² = 55458472228152968, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166520971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 257051 + ... + 257697.

It is an arithmetic number, because the mean of its divisors is an integer number (8879220).

Almost surely, 2^166520978 is an apocalyptic number.

166520978 is a deficient number, since it is larger than the sum of its proper divisors (117614062).

166520978 is a wasteful number, since it uses less digits than its factorization.

166520978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 166520978 is about 12904.3007559495. The cubic root of 166520978 is about 550.1608102776.

The spelling of 166520978 in words is "one hundred sixty-six million, five hundred twenty thousand, nine hundred seventy-eight".