661026669 has 8 divisors (see below), whose sum is σ = 882530112. Its totient is φ = 440103840.

The previous prime is 661026643. The next prime is 661026673. The reversal of 661026669 is 966620166.

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

It is not a de Polignac number, because 661026669 - 2⁵ = 661026637 is a prime.

It is a super-2 number, since 2×661026669² = 873912514258471122, 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 661026669.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661026629) 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, 142489 + ... + 147054.

It is an arithmetic number, because the mean of its divisors is an integer number (110316264).

Almost surely, 2^661026669 is an apocalyptic number.

It is an amenable number.

661026669 is a deficient number, since it is larger than the sum of its proper divisors (221503443).

661026669 is a wasteful number, since it uses less digits than its factorization.

661026669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290307.

The product of its (nonzero) digits is 139968, while the sum is 42.

The square root of 661026669 is about 25710.4389110727. The cubic root of 661026669 is about 871.1099889529.

It can be divided in two parts, 66102 and 6669, that added together give a triangular number (72771 = T₃₈₁).

The spelling of 661026669 in words is "six hundred sixty-one million, twenty-six thousand, six hundred sixty-nine".