1994128403 has 4 divisors (see below), whose sum is σ = 2002687128. Its totient is φ = 1985569680.

The previous prime is 1994128379. The next prime is 1994128429. The reversal of 1994128403 is 3048214991.

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

It is a cyclic number.

It is not a de Polignac number, because 1994128403 - 2¹⁰ = 1994127379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1994125403) 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, 4279013 + ... + 4279478.

It is an arithmetic number, because the mean of its divisors is an integer number (500671782).

Almost surely, 2^1994128403 is an apocalyptic number.

1994128403 is a deficient number, since it is larger than the sum of its proper divisors (8558725).

1994128403 is an equidigital number, since it uses as much as digits as its factorization.

1994128403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8558724.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 1994128403 is about 44655.6648478107. The cubic root of 1994128403 is about 1258.6868832414.

The spelling of 1994128403 in words is "one billion, nine hundred ninety-four million, one hundred twenty-eight thousand, four hundred three".