18648739 has 4 divisors (see below), whose sum is σ = 19000656. Its totient is φ = 18296824.

The previous prime is 18648733. The next prime is 18648761. The reversal of 18648739 is 93784681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93784681 = 71 ⋅1320911.

It is a cyclic number.

It is not a de Polignac number, because 18648739 - 2¹³ = 18640547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18648733) 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, 175879 + ... + 175984.

It is an arithmetic number, because the mean of its divisors is an integer number (4750164).

Almost surely, 2^18648739 is an apocalyptic number.

18648739 is a deficient number, since it is larger than the sum of its proper divisors (351917).

18648739 is an equidigital number, since it uses as much as digits as its factorization.

18648739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351916.

The product of its digits is 290304, while the sum is 46.

The square root of 18648739 is about 4318.4185762846. The cubic root of 18648739 is about 265.1855304544.

The spelling of 18648739 in words is "eighteen million, six hundred forty-eight thousand, seven hundred thirty-nine".