1664620305 has 16 divisors (see below), whose sum is σ = 2803571520. Its totient is φ = 841071168.

The previous prime is 1664620301. The next prime is 1664620313. The reversal of 1664620305 is 5030264661.

It is not a de Polignac number, because 1664620305 - 2² = 1664620301 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1664620301) 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, 2920102 + ... + 2920671.

It is an arithmetic number, because the mean of its divisors is an integer number (175223220).

Almost surely, 2^1664620305 is an apocalyptic number.

1664620305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1664620305 is a deficient number, since it is larger than the sum of its proper divisors (1138951215).

1664620305 is a wasteful number, since it uses less digits than its factorization.

1664620305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5840800.

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 1664620305 is about 40799.7586389920. The cubic root of 1664620305 is about 1185.1456567560.

Adding to 1664620305 its reverse (5030264661), we get a palindrome (6694884966).

The spelling of 1664620305 in words is "one billion, six hundred sixty-four million, six hundred twenty thousand, three hundred five".