20156811 has 4 divisors (see below), whose sum is σ = 26875752. Its totient is φ = 13437872.

The previous prime is 20156797. The next prime is 20156821. The reversal of 20156811 is 11865102.

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 20156811 - 2⁷ = 20156683 is a prime.

It is a zygodrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (20156821) 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, 3359466 + ... + 3359471.

It is an arithmetic number, because the mean of its divisors is an integer number (6718938).

Almost surely, 2^20156811 is an apocalyptic number.

20156811 is a deficient number, since it is larger than the sum of its proper divisors (6718941).

20156811 is an equidigital number, since it uses as much as digits as its factorization.

20156811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6718940.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 20156811 is about 4489.6337267087. The cubic root of 20156811 is about 272.1493331871.

The spelling of 20156811 in words is "twenty million, one hundred fifty-six thousand, eight hundred eleven".