18994957 has 4 divisors (see below), whose sum is σ = 19055196. Its totient is φ = 18934720.

The previous prime is 18994907. The next prime is 18994979. The reversal of 18994957 is 75949981.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6702921 + 12292036 = 2589^2 + 3506^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18994957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18994907) 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, 29644 + ... + 30277.

It is an arithmetic number, because the mean of its divisors is an integer number (4763799).

Almost surely, 2^18994957 is an apocalyptic number.

It is an amenable number.

18994957 is a deficient number, since it is larger than the sum of its proper divisors (60239).

18994957 is an equidigital number, since it uses as much as digits as its factorization.

18994957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60238.

The product of its digits is 816480, while the sum is 52.

The square root of 18994957 is about 4358.3204333780. The cubic root of 18994957 is about 266.8165544507.

The spelling of 18994957 in words is "eighteen million, nine hundred ninety-four thousand, nine hundred fifty-seven".