1664277520 has 80 divisors (see below), whose sum is σ = 4088309760. Its totient is φ = 629038592.

The previous prime is 1664277499. The next prime is 1664277529. The reversal of 1664277520 is 257724661.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (1664277529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101409 + ... + 116671.

It is an arithmetic number, because the mean of its divisors is an integer number (51103872).

Almost surely, 2^1664277520 is an apocalyptic number.

1664277520 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 1664277520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2044154880).

1664277520 is an abundant number, since it is smaller than the sum of its proper divisors (2424032240).

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

1664277520 is a wasteful number, since it uses less digits than its factorization.

1664277520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15352 (or 15346 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 40.

The square root of 1664277520 is about 40795.5576012879. The cubic root of 1664277520 is about 1185.0643012578.

The spelling of 1664277520 in words is "one billion, six hundred sixty-four million, two hundred seventy-seven thousand, five hundred twenty".