667707281 has 16 divisors (see below), whose sum is σ = 710110800. Its totient is φ = 626841600.

The previous prime is 667707277. The next prime is 667707323. The reversal of 667707281 is 182707766.

It can be written as a sum of positive squares in 8 ways, for example, as 10297681 + 657409600 = 3209^2 + 25640^2 .

It is a cyclic number.

It is not a de Polignac number, because 667707281 - 2² = 667707277 is a prime.

It is a super-2 number, since 2×667707281² = 891666026200825922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667707241) 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, 155321 + ... + 159561.

It is an arithmetic number, because the mean of its divisors is an integer number (44381925).

Almost surely, 2^667707281 is an apocalyptic number.

667707281 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

667707281 is a deficient number, since it is larger than the sum of its proper divisors (42403519).

667707281 is a wasteful number, since it uses less digits than its factorization.

667707281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4420.

The product of its (nonzero) digits is 197568, while the sum is 44.

The square root of 667707281 is about 25840.0325270693. The cubic root of 667707281 is about 874.0347586223.

The spelling of 667707281 in words is "six hundred sixty-seven million, seven hundred seven thousand, two hundred eighty-one".