166621370 has 16 divisors (see below), whose sum is σ = 300139560. Its totient is φ = 66599424.

The previous prime is 166621337. The next prime is 166621379. The reversal of 166621370 is 73126661.

It can be written as a sum of positive squares in 4 ways, for example, as 118831801 + 47789569 = 10901^2 + 6913^2 .

It is not an unprimeable number, because it can be changed into a prime (166621379) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10166 + ... + 20894.

Almost surely, 2^166621370 is an apocalyptic number.

166621370 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

166621370 is a deficient number, since it is larger than the sum of its proper divisors (133518190).

166621370 is a wasteful number, since it uses less digits than its factorization.

166621370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12289.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 166621370 is about 12908.1900357874. The cubic root of 166621370 is about 550.2713481992.

The spelling of 166621370 in words is "one hundred sixty-six million, six hundred twenty-one thousand, three hundred seventy".