18491961 has 8 divisors (see below), whose sum is σ = 24693120. Its totient is φ = 12309392.

The previous prime is 18491951. The next prime is 18491969. The reversal of 18491961 is 16919481.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18491961 - 2⁵ = 18491929 is a prime.

It is a Curzon 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 7 ways as a sum of consecutive naturals, for example, 2130 + ... + 6443.

It is an arithmetic number, because the mean of its divisors is an integer number (3086640).

Almost surely, 2^18491961 is an apocalyptic number.

It is an amenable number.

18491961 is a deficient number, since it is larger than the sum of its proper divisors (6201159).

18491961 is an equidigital number, since it uses as much as digits as its factorization.

18491961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9295.

The product of its digits is 15552, while the sum is 39.

The square root of 18491961 is about 4300.2280172103. The cubic root of 18491961 is about 264.4403091898.

The spelling of 18491961 in words is "eighteen million, four hundred ninety-one thousand, nine hundred sixty-one".