1664745615 has 48 divisors (see below), whose sum is σ = 3222649248. Its totient is φ = 819559296.

The previous prime is 1664745613. The next prime is 1664745617. The reversal of 1664745615 is 5165474661.

1664745615 is a `hidden beast` number, since 16 + 6 + 4 + 74 + 561 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (1664745613) and next prime (1664745617).

It is not a de Polignac number, because 1664745615 - 2¹ = 1664745613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664745613) 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 47 ways as a sum of consecutive naturals, for example, 36904 + ... + 68493.

It is an arithmetic number, because the mean of its divisors is an integer number (67138526).

Almost surely, 2^1664745615 is an apocalyptic number.

1664745615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1664745615 is a deficient number, since it is larger than the sum of its proper divisors (1557903633).

1664745615 is a wasteful number, since it uses less digits than its factorization.

1664745615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105430 (or 105418 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 1664745615 is about 40801.2942809416. The cubic root of 1664745615 is about 1185.1753946438.

The spelling of 1664745615 in words is "one billion, six hundred sixty-four million, seven hundred forty-five thousand, six hundred fifteen".