1664147540 has 48 divisors (see below), whose sum is σ = 3826025280. Its totient is φ = 602983680.

The previous prime is 1664147539. The next prime is 1664147603. The reversal of 1664147540 is 457414661.

It is a junction number, because it is equal to n+sod(n) for n = 1664147494 and 1664147503.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48896 + ... + 75624.

It is an arithmetic number, because the mean of its divisors is an integer number (79708860).

Almost surely, 2^1664147540 is an apocalyptic number.

1664147540 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 1664147540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1913012640).

1664147540 is an abundant number, since it is smaller than the sum of its proper divisors (2161877740).

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

1664147540 is a wasteful number, since it uses less digits than its factorization.

1664147540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27032 (or 27030 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 1664147540 is about 40793.9645045686. The cubic root of 1664147540 is about 1185.0334492982.

The spelling of 1664147540 in words is "one billion, six hundred sixty-four million, one hundred forty-seven thousand, five hundred forty".