18943961 has 4 divisors (see below), whose sum is σ = 19347072. Its totient is φ = 18540852.

The previous prime is 18943957. The next prime is 18943993. The reversal of 18943961 is 16934981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18943961 - 2² = 18943957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18943901) 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, 201485 + ... + 201578.

It is an arithmetic number, because the mean of its divisors is an integer number (4836768).

Almost surely, 2^18943961 is an apocalyptic number.

It is an amenable number.

18943961 is a deficient number, since it is larger than the sum of its proper divisors (403111).

18943961 is an equidigital number, since it uses as much as digits as its factorization.

18943961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403110.

The product of its digits is 46656, while the sum is 41.

The square root of 18943961 is about 4352.4660825789. The cubic root of 18943961 is about 266.5775651971.

The spelling of 18943961 in words is "eighteen million, nine hundred forty-three thousand, nine hundred sixty-one".