667703561 has 4 divisors (see below), whose sum is σ = 763089792. Its totient is φ = 572317332.

The previous prime is 667703557. The next prime is 667703563. The reversal of 667703561 is 165307766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 667703561 - 2² = 667703557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667703563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47693105 + ... + 47693118.

It is an arithmetic number, because the mean of its divisors is an integer number (190772448).

Almost surely, 2^667703561 is an apocalyptic number.

It is an amenable number.

667703561 is a deficient number, since it is larger than the sum of its proper divisors (95386231).

667703561 is an equidigital number, since it uses as much as digits as its factorization.

667703561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95386230.

The product of its (nonzero) digits is 158760, while the sum is 41.

The square root of 667703561 is about 25839.9605456355. The cubic root of 667703561 is about 874.0331354483.

The spelling of 667703561 in words is "six hundred sixty-seven million, seven hundred three thousand, five hundred sixty-one".