669542400 has 216 divisors, whose sum is σ = 2399514390. Its totient is φ = 178421760.

The previous prime is 669542389. The next prime is 669542411. The reversal of 669542400 is 4245966.

It is an interprime number because it is at equal distance from previous prime (669542389) and next prime (669542411).

It can be written as a sum of positive squares in 3 ways, for example, as 637461504 + 32080896 = 25248^2 + 5664^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 460074 + ... + 461526.

Almost surely, 2^669542400 is an apocalyptic number.

669542400 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 669542400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1199757195).

669542400 is an abundant number, since it is smaller than the sum of its proper divisors (1729971990).

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

669542400 is a wasteful number, since it uses less digits than its factorization.

669542400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1491 (or 1463 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 669542400 is about 25875.5173861316. The cubic root of 669542400 is about 874.8347551898.

The spelling of 669542400 in words is "six hundred sixty-nine million, five hundred forty-two thousand, four hundred".