1667221281 has 24 divisors (see below), whose sum is σ = 2717732160. Its totient is φ = 975592800.

The previous prime is 1667221277. The next prime is 1667221301. The reversal of 1667221281 is 1821227661.

It is not a de Polignac number, because 1667221281 - 2² = 1667221277 is a prime.

It is a super-2 number, since 2×1667221281² = 5559253599638561922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1667221201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 287485 + ... + 293226.

It is an arithmetic number, because the mean of its divisors is an integer number (113238840).

Almost surely, 2^1667221281 is an apocalyptic number.

1667221281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1667221281 is a deficient number, since it is larger than the sum of its proper divisors (1050510879).

1667221281 is a wasteful number, since it uses less digits than its factorization.

1667221281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580757 (or 580754 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 1667221281 is about 40831.6210919919. The cubic root of 1667221281 is about 1185.7626005121.

The spelling of 1667221281 in words is "one billion, six hundred sixty-seven million, two hundred twenty-one thousand, two hundred eighty-one".