1664123140 has 24 divisors (see below), whose sum is σ = 3646601280. Its totient is φ = 636707808.

The previous prime is 1664123107. The next prime is 1664123141. The reversal of 1664123140 is 413214661.

It is a junction number, because it is equal to n+sod(n) for n = 1664123099 and 1664123108.

It is not an unprimeable number, because it can be changed into a prime (1664123141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1808370 + ... + 1809289.

It is an arithmetic number, because the mean of its divisors is an integer number (151941720).

Almost surely, 2^1664123140 is an apocalyptic number.

1664123140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664123140 is an abundant number, since it is smaller than the sum of its proper divisors (1982478140).

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

1664123140 is a wasteful number, since it uses less digits than its factorization.

1664123140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3617691 (or 3617689 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1664123140 is about 40793.6654396243. The cubic root of 1664123140 is about 1185.0276575527.

The spelling of 1664123140 in words is "one billion, six hundred sixty-four million, one hundred twenty-three thousand, one hundred forty".