661487017 has 8 divisors (see below), whose sum is σ = 716687136. Its totient is φ = 608096832.

The previous prime is 661486997. The next prime is 661487023. The reversal of 661487017 is 710784166.

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

It is a cyclic number.

It is not a de Polignac number, because 661487017 - 2²⁷ = 527269289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661487027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 451723 + ... + 453184.

It is an arithmetic number, because the mean of its divisors is an integer number (89585892).

Almost surely, 2^661487017 is an apocalyptic number.

It is an amenable number.

661487017 is a deficient number, since it is larger than the sum of its proper divisors (55200119).

661487017 is a wasteful number, since it uses less digits than its factorization.

661487017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 904967.

The product of its (nonzero) digits is 56448, while the sum is 40.

The square root of 661487017 is about 25719.3899033395. The cubic root of 661487017 is about 871.3121596598.

The spelling of 661487017 in words is "six hundred sixty-one million, four hundred eighty-seven thousand, seventeen".