1664156611623 has 16 divisors (see below), whose sum is σ = 2420744256000. Its totient is φ = 1008516089280.

The previous prime is 1664156611619. The next prime is 1664156611651. The reversal of 1664156611623 is 3261166514661.

It is not a de Polignac number, because 1664156611623 - 2² = 1664156611619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664156611823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1058598 + ... + 2109251.

It is an arithmetic number, because the mean of its divisors is an integer number (151296516000).

Almost surely, 2^{1664156611623} is an apocalyptic number.

1664156611623 is a deficient number, since it is larger than the sum of its proper divisors (756587644377).

1664156611623 is a wasteful number, since it uses less digits than its factorization.

1664156611623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3183782.

The product of its digits is 933120, while the sum is 48.

The spelling of 1664156611623 in words is "one trillion, six hundred sixty-four billion, one hundred fifty-six million, six hundred eleven thousand, six hundred twenty-three".