661588669 has 16 divisors (see below), whose sum is σ = 792570240. Its totient is φ = 540368640.

The previous prime is 661588663. The next prime is 661588679. The reversal of 661588669 is 966885166.

It is a happy number.

It is not a de Polignac number, because 661588669 - 2³ = 661588661 is a prime.

It is a super-2 number, since 2×661588669² = 875399133898383122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661588661) 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, 14464 + ... + 39145.

It is an arithmetic number, because the mean of its divisors is an integer number (49535640).

Almost surely, 2^661588669 is an apocalyptic number.

It is an amenable number.

661588669 is a deficient number, since it is larger than the sum of its proper divisors (130981571).

661588669 is a wasteful number, since it uses less digits than its factorization.

661588669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53700.

The product of its digits is 3732480, while the sum is 55.

The square root of 661588669 is about 25721.3660018281. The cubic root of 661588669 is about 871.3567894534.

The spelling of 661588669 in words is "six hundred sixty-one million, five hundred eighty-eight thousand, six hundred sixty-nine".