669349881 has 6 divisors (see below), whose sum is σ = 966838730. Its totient is φ = 446233248.

The previous prime is 669349847. The next prime is 669349903. The reversal of 669349881 is 188943966.

669349881 is a `hidden beast` number, since 66 + 93 + 498 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 661312656 + 8037225 = 25716^2 + 2835^2 .

It is a de Polignac number, because none of the positive numbers 2^k-669349881 is a prime.

It is a super-2 number, since 2×669349881² = 896058526389428322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669349831) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37186096 + ... + 37186113.

Almost surely, 2^669349881 is an apocalyptic number.

It is an amenable number.

669349881 is a deficient number, since it is larger than the sum of its proper divisors (297488849).

669349881 is a wasteful number, since it uses less digits than its factorization.

669349881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74372215 (or 74372212 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 54.

The square root of 669349881 is about 25871.7970191481. The cubic root of 669349881 is about 874.7508976888.

The spelling of 669349881 in words is "six hundred sixty-nine million, three hundred forty-nine thousand, eight hundred eighty-one".