18699994 has 4 divisors (see below), whose sum is σ = 28049994. Its totient is φ = 9349996.

The previous prime is 18699973. The next prime is 18699997. The reversal of 18699994 is 49999681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49999681 = 47 ⋅1063823.

It can be written as a sum of positive squares in only one way, i.e., 17749369 + 950625 = 4213^2 + 975^2 .

It is not an unprimeable number, because it can be changed into a prime (18699997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4674997 + ... + 4675000.

Almost surely, 2^18699994 is an apocalyptic number.

18699994 is a deficient number, since it is larger than the sum of its proper divisors (9350000).

18699994 is an equidigital number, since it uses as much as digits as its factorization.

18699994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9349999.

The product of its digits is 1259712, while the sum is 55.

The square root of 18699994 is about 4324.3489683419. The cubic root of 18699994 is about 265.4282573395.

The spelling of 18699994 in words is "eighteen million, six hundred ninety-nine thousand, nine hundred ninety-four".