18939539 has 8 divisors (see below), whose sum is σ = 19320000. Its totient is φ = 18562752.

The previous prime is 18939533. The next prime is 18939551. The reversal of 18939539 is 93593981.

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 18939539 - 2¹⁶ = 18874003 is a prime.

It is a super-2 number, since 2×18939539² = 717412275065042, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18939493 and 18939502.

It is not an unprimeable number, because it can be changed into a prime (18939533) 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 7 ways as a sum of consecutive naturals, for example, 10967 + ... + 12575.

It is an arithmetic number, because the mean of its divisors is an integer number (2415000).

Almost surely, 2^18939539 is an apocalyptic number.

18939539 is a deficient number, since it is larger than the sum of its proper divisors (380461).

18939539 is a wasteful number, since it uses less digits than its factorization.

18939539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1837.

The product of its digits is 262440, while the sum is 47.

The square root of 18939539 is about 4351.9580650553. The cubic root of 18939539 is about 266.5568215992.

The spelling of 18939539 in words is "eighteen million, nine hundred thirty-nine thousand, five hundred thirty-nine".