1556164665 has 72 divisors (see below), whose sum is σ = 2993687424. Its totient is φ = 747172800.

The previous prime is 1556164663. The next prime is 1556164703. The reversal of 1556164665 is 5664616551.

It is not a de Polignac number, because 1556164665 - 2¹ = 1556164663 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1556164665.

It is not an unprimeable number, because it can be changed into a prime (1556164663) 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 71 ways as a sum of consecutive naturals, for example, 581280 + ... + 583950.

It is an arithmetic number, because the mean of its divisors is an integer number (41578992).

Almost surely, 2^1556164665 is an apocalyptic number.

1556164665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1556164665 is a deficient number, since it is larger than the sum of its proper divisors (1437522759).

1556164665 is a wasteful number, since it uses less digits than its factorization.

1556164665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2811 (or 2797 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The square root of 1556164665 is about 39448.2530031432. The cubic root of 1556164665 is about 1158.8267628929.

The spelling of 1556164665 in words is "one billion, five hundred fifty-six million, one hundred sixty-four thousand, six hundred sixty-five".