669429540 has 144 divisors (see below), whose sum is σ = 2194989888. Its totient is φ = 164166912.

The previous prime is 669429529. The next prime is 669429569. The reversal of 669429540 is 45924966.

669429540 is a `hidden beast` number, since 6 + 69 + 42 + 9 + 540 = 666.

It is a super-2 number, since 2×669429540² = 896271818049223200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1223547 + ... + 1224093.

Almost surely, 2^669429540 is an apocalyptic number.

669429540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669429540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1097494944).

669429540 is an abundant number, since it is smaller than the sum of its proper divisors (1525560348).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669429540 is a wasteful number, since it uses less digits than its factorization.

669429540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098 (or 1093 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 669429540 is about 25873.3364682640. The cubic root of 669429540 is about 874.7855975370.

The spelling of 669429540 in words is "six hundred sixty-nine million, four hundred twenty-nine thousand, five hundred forty".