20143961491 has 4 divisors (see below), whose sum is σ = 20144594800. Its totient is φ = 20143328184.

The previous prime is 20143961489. The next prime is 20143961507. The reversal of 20143961491 is 19416934102.

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 20143961491 - 2¹ = 20143961489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20143961441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266271 + ... + 333448.

It is an arithmetic number, because the mean of its divisors is an integer number (5036148700).

Almost surely, 2^20143961491 is an apocalyptic number.

20143961491 is a deficient number, since it is larger than the sum of its proper divisors (633309).

20143961491 is an equidigital number, since it uses as much as digits as its factorization.

20143961491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633308.

The product of its (nonzero) digits is 46656, while the sum is 40.

The spelling of 20143961491 in words is "twenty billion, one hundred forty-three million, nine hundred sixty-one thousand, four hundred ninety-one".