20911906147 has 4 divisors (see below), whose sum is σ = 22812988536. Its totient is φ = 19010823760.

The previous prime is 20911906139. The next prime is 20911906181. The reversal of 20911906147 is 74160911902.

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 20911906147 - 2³ = 20911906139 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20911906247) 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, 950541178 + ... + 950541199.

It is an arithmetic number, because the mean of its divisors is an integer number (5703247134).

Almost surely, 2^20911906147 is an apocalyptic number.

20911906147 is a deficient number, since it is larger than the sum of its proper divisors (1901082389).

20911906147 is a wasteful number, since it uses less digits than its factorization.

20911906147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1901082388.

The product of its (nonzero) digits is 27216, while the sum is 40.

The spelling of 20911906147 in words is "twenty billion, nine hundred eleven million, nine hundred six thousand, one hundred forty-seven".