18491964 has 12 divisors (see below), whose sum is σ = 43147944. Its totient is φ = 6163984.

The previous prime is 18491951. The next prime is 18491969. The reversal of 18491964 is 46919481.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18491969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 770487 + ... + 770510.

It is an arithmetic number, because the mean of its divisors is an integer number (3595662).

Almost surely, 2^18491964 is an apocalyptic number.

It is an amenable number.

18491964 is an abundant number, since it is smaller than the sum of its proper divisors (24655980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18491964 is a wasteful number, since it uses less digits than its factorization.

18491964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1541004 (or 1541002 counting only the distinct ones).

The product of its digits is 62208, while the sum is 42.

The square root of 18491964 is about 4300.2283660289. The cubic root of 18491964 is about 264.4403234900.

The spelling of 18491964 in words is "eighteen million, four hundred ninety-one thousand, nine hundred sixty-four".