18448294978 has 4 divisors (see below), whose sum is σ = 27672442470. Its totient is φ = 9224147488.

The previous prime is 18448294973. The next prime is 18448294981. The reversal of 18448294978 is 87949284481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87949284481 = 208003 ⋅422827.

It can be written as a sum of positive squares in only one way, i.e., 17252034409 + 1196260569 = 131347^2 + 34587^2 .

It is not an unprimeable number, because it can be changed into a prime (18448294973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4612073743 + ... + 4612073746.

Almost surely, 2^18448294978 is an apocalyptic number.

18448294978 is a deficient number, since it is larger than the sum of its proper divisors (9224147492).

18448294978 is an equidigital number, since it uses as much as digits as its factorization.

18448294978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9224147491.

The product of its digits is 37158912, while the sum is 64.

The spelling of 18448294978 in words is "eighteen billion, four hundred forty-eight million, two hundred ninety-four thousand, nine hundred seventy-eight".