1669040640 has 240 divisors, whose sum is σ = 5996678688. Its totient is φ = 444911616.

The previous prime is 1669040629. The next prime is 1669040687. The reversal of 1669040640 is 460409661.

1669040640 is a `hidden beast` number, since 1 + 6 + 6 + 9 + 0 + 4 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 1669040595 and 1669040604.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 620739 + ... + 623421.

Almost surely, 2^1669040640 is an apocalyptic number.

1669040640 is a gapful number since it is divisible by the number (10) 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 1669040640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2998339344).

1669040640 is an abundant number, since it is smaller than the sum of its proper divisors (4327638048).

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

1669040640 is an frugal number, since it uses more digits than its factorization.

1669040640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2721 (or 2693 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 1669040640 is about 40853.8938168689. The cubic root of 1669040640 is about 1186.1937657548.

The spelling of 1669040640 in words is "one billion, six hundred sixty-nine million, forty thousand, six hundred forty".