20491967267 has 4 divisors (see below), whose sum is σ = 21570491880. Its totient is φ = 19413442656.

The previous prime is 20491967233. The next prime is 20491967281. The reversal of 20491967267 is 76276919402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76276919402 = 2 ⋅38138459701.

It is a cyclic number.

It is not a de Polignac number, because 20491967267 - 2¹⁴ = 20491950883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20491967207) 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, 539262278 + ... + 539262315.

It is an arithmetic number, because the mean of its divisors is an integer number (5392622970).

Almost surely, 2^20491967267 is an apocalyptic number.

20491967267 is a deficient number, since it is larger than the sum of its proper divisors (1078524613).

20491967267 is a wasteful number, since it uses less digits than its factorization.

20491967267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078524612.

The product of its (nonzero) digits is 2286144, while the sum is 53.

The spelling of 20491967267 in words is "twenty billion, four hundred ninety-one million, nine hundred sixty-seven thousand, two hundred sixty-seven".