667521417 has 8 divisors (see below), whose sum is σ = 902221024. Its totient is φ = 438918048.

The previous prime is 667521389. The next prime is 667521427. The reversal of 667521417 is 714125766.

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

It is not a de Polignac number, because 667521417 - 2⁷ = 667521289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667521427) 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, 1523803 + ... + 1524240.

It is an arithmetic number, because the mean of its divisors is an integer number (112777628).

Almost surely, 2^667521417 is an apocalyptic number.

It is an amenable number.

667521417 is a deficient number, since it is larger than the sum of its proper divisors (234699607).

667521417 is a wasteful number, since it uses less digits than its factorization.

667521417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3048119.

The product of its digits is 70560, while the sum is 39.

The square root of 667521417 is about 25836.4358416559. The cubic root of 667521417 is about 873.9536518875.

The spelling of 667521417 in words is "six hundred sixty-seven million, five hundred twenty-one thousand, four hundred seventeen".