659890721 has 8 divisors (see below), whose sum is σ = 761209920. Its totient is φ = 560333808.

The previous prime is 659890663. The next prime is 659890799. The reversal of 659890721 is 127098956.

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 659890721 - 2²² = 655696417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (659892721) 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, 439766 + ... + 441263.

It is an arithmetic number, because the mean of its divisors is an integer number (95151240).

Almost surely, 2^659890721 is an apocalyptic number.

It is an amenable number.

659890721 is a deficient number, since it is larger than the sum of its proper divisors (101319199).

659890721 is a wasteful number, since it uses less digits than its factorization.

659890721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881143.

The product of its (nonzero) digits is 272160, while the sum is 47.

The square root of 659890721 is about 25688.3382296325. The cubic root of 659890721 is about 870.6107135763.

The spelling of 659890721 in words is "six hundred fifty-nine million, eight hundred ninety thousand, seven hundred twenty-one".