18021611513623 has 8 divisors (see below), whose sum is σ = 19296107504640. Its totient is φ = 16770937877760.

The previous prime is 18021611513611. The next prime is 18021611513639. The reversal of 18021611513623 is 32631511612081.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18021611513623 - 2³⁷ = 17884172560151 is a prime.

It is a super-2 number, since 2×18021611513623² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18021611513023) 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 7 ways as a sum of consecutive naturals, for example, 5955587223 + ... + 5955590248.

It is an arithmetic number, because the mean of its divisors is an integer number (2412013438080).

Almost surely, 2^{18021611513623} is an apocalyptic number.

18021611513623 is a deficient number, since it is larger than the sum of its proper divisors (1274495991017).

18021611513623 is a wasteful number, since it uses less digits than its factorization.

18021611513623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11911177577.

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 18021611513623 in words is "eighteen trillion, twenty-one billion, six hundred eleven million, five hundred thirteen thousand, six hundred twenty-three".