18953939 has 4 divisors (see below), whose sum is σ = 19213656. Its totient is φ = 18694224.

The previous prime is 18953923. The next prime is 18953941. The reversal of 18953939 is 93935981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18953939 - 2⁴ = 18953923 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18953893 and 18953902.

It is not an unprimeable number, because it can be changed into a prime (18953639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129749 + ... + 129894.

It is an arithmetic number, because the mean of its divisors is an integer number (4803414).

Almost surely, 2^18953939 is an apocalyptic number.

18953939 is a deficient number, since it is larger than the sum of its proper divisors (259717).

18953939 is an equidigital number, since it uses as much as digits as its factorization.

18953939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259716.

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

The square root of 18953939 is about 4353.6121784100. The cubic root of 18953939 is about 266.6243601287.

The spelling of 18953939 in words is "eighteen million, nine hundred fifty-three thousand, nine hundred thirty-nine".