1664720232 has 128 divisors (see below), whose sum is σ = 4930252800. Its totient is φ = 458535168.

The previous prime is 1664720221. The next prime is 1664720303. The reversal of 1664720232 is 2320274661.

It is a junction number, because it is equal to n+sod(n) for n = 1664720193 and 1664720202.

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, 569238 + ... + 572154.

It is an arithmetic number, because the mean of its divisors is an integer number (38517600).

Almost surely, 2^1664720232 is an apocalyptic number.

1664720232 is a gapful number since it is divisible by the number (12) 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 1664720232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2465126400).

1664720232 is an abundant number, since it is smaller than the sum of its proper divisors (3265532568).

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

1664720232 is a wasteful number, since it uses less digits than its factorization.

1664720232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3055 (or 3051 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 1664720232 is about 40800.9832234470. The cubic root of 1664720232 is about 1185.1693710088.

Adding to 1664720232 its reverse (2320274661), we get a palindrome (3984994893).

The spelling of 1664720232 in words is "one billion, six hundred sixty-four million, seven hundred twenty thousand, two hundred thirty-two".