1666722290 has 8 divisors (see below), whose sum is σ = 3000100140. Its totient is φ = 666688912.

The previous prime is 1666722289. The next prime is 1666722353. The reversal of 1666722290 is 922276661.

It can be written as a sum of positive squares in 2 ways, for example, as 1492508689 + 174213601 = 38633^2 + 13199^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83336105 + ... + 83336124.

Almost surely, 2^1666722290 is an apocalyptic number.

1666722290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1666722290 is a deficient number, since it is larger than the sum of its proper divisors (1333377850).

1666722290 is a wasteful number, since it uses less digits than its factorization.

1666722290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166672236.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 1666722290 is about 40825.5102846247. The cubic root of 1666722290 is about 1185.6442911008.

The spelling of 1666722290 in words is "one billion, six hundred sixty-six million, seven hundred twenty-two thousand, two hundred ninety".