1667345640 has 128 divisors (see below), whose sum is σ = 5139763200. Its totient is φ = 432472320.

The previous prime is 1667345591. The next prime is 1667345651. The reversal of 1667345640 is 465437661.

It is a junction number, because it is equal to n+sod(n) for n = 1667345592 and 1667345601.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1604241 + ... + 1605279.

It is an arithmetic number, because the mean of its divisors is an integer number (40154400).

Almost surely, 2^1667345640 is an apocalyptic number.

1667345640 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 1667345640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2569881600).

1667345640 is an abundant number, since it is smaller than the sum of its proper divisors (3472417560).

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

1667345640 is a wasteful number, since it uses less digits than its factorization.

1667345640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407 (or 1403 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 42.

The square root of 1667345640 is about 40833.1438907170. The cubic root of 1667345640 is about 1185.7920820186.

The spelling of 1667345640 in words is "one billion, six hundred sixty-seven million, three hundred forty-five thousand, six hundred forty".