661986269 has 4 divisors (see below), whose sum is σ = 756555744. Its totient is φ = 567416796.

The previous prime is 661986251. The next prime is 661986359. The reversal of 661986269 is 962689166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 661986269 - 2¹⁶ = 661920733 is a prime.

It is a super-2 number, since 2×661986269² = 876451640689080722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 661986269.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661986229) 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 3 ways as a sum of consecutive naturals, for example, 47284727 + ... + 47284740.

It is an arithmetic number, because the mean of its divisors is an integer number (189138936).

Almost surely, 2^661986269 is an apocalyptic number.

It is an amenable number.

661986269 is a deficient number, since it is larger than the sum of its proper divisors (94569475).

661986269 is an equidigital number, since it uses as much as digits as its factorization.

661986269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94569474.

The product of its digits is 1679616, while the sum is 53.

The square root of 661986269 is about 25729.0938239185. The cubic root of 661986269 is about 871.5313098141.

The spelling of 661986269 in words is "six hundred sixty-one million, nine hundred eighty-six thousand, two hundred sixty-nine".