661787269 has 24 divisors (see below), whose sum is σ = 784920672. Its totient is φ = 553101120.

The previous prime is 661787263. The next prime is 661787281. The reversal of 661787269 is 962787166.

It is a happy number.

It is not a de Polignac number, because 661787269 - 2³ = 661787261 is a prime.

It is a super-2 number, since 2×661787269² = 875924778820956722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661787261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 588742 + ... + 589864.

It is an arithmetic number, because the mean of its divisors is an integer number (32705028).

Almost surely, 2^661787269 is an apocalyptic number.

It is an amenable number.

661787269 is a deficient number, since it is larger than the sum of its proper divisors (123133403).

661787269 is a wasteful number, since it uses less digits than its factorization.

661787269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1477 (or 1464 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 52.

The square root of 661787269 is about 25725.2263158169. The cubic root of 661787269 is about 871.4439705844.

The spelling of 661787269 in words is "six hundred sixty-one million, seven hundred eighty-seven thousand, two hundred sixty-nine".