18928013 has 4 divisors (see below), whose sum is σ = 20384028. Its totient is φ = 17472000.

The previous prime is 18928003. The next prime is 18928027. The reversal of 18928013 is 31082981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31082981 = 1721 ⋅18061.

It can be written as a sum of positive squares in 2 ways, for example, as 6061444 + 12866569 = 2462^2 + 3587^2 .

It is not a de Polignac number, because 18928013 - 2¹⁸ = 18665869 is a prime.

It is a super-2 number, since 2×18928013² = 716539352256338, which 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 (18928003) 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, 727988 + ... + 728013.

It is an arithmetic number, because the mean of its divisors is an integer number (5096007).

Almost surely, 2^18928013 is an apocalyptic number.

18928013 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18928013 is a deficient number, since it is larger than the sum of its proper divisors (1456015).

18928013 is a wasteful number, since it uses less digits than its factorization.

18928013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1456014.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 18928013 is about 4350.6336320127. The cubic root of 18928013 is about 266.5027379636.

The spelling of 18928013 in words is "eighteen million, nine hundred twenty-eight thousand, thirteen".