1664998440 has 96 divisors (see below), whose sum is σ = 5810525280. Its totient is φ = 380569728.

The previous prime is 1664998421. The next prime is 1664998457. The reversal of 1664998440 is 448994661.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135702 + ... + 147461.

It is an arithmetic number, because the mean of its divisors is an integer number (60526305).

Almost surely, 2^1664998440 is an apocalyptic number.

1664998440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664998440 is an abundant number, since it is smaller than the sum of its proper divisors (4145526840).

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

1664998440 is a wasteful number, since it uses less digits than its factorization.

1664998440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283191 (or 283180 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 51.

The square root of 1664998440 is about 40804.3924106217. The cubic root of 1664998440 is about 1185.2353891557.

The spelling of 1664998440 in words is "one billion, six hundred sixty-four million, nine hundred ninety-eight thousand, four hundred forty".