20156011 has 4 divisors (see below), whose sum is σ = 20245032. Its totient is φ = 20066992.

The previous prime is 20155987. The next prime is 20156021. The reversal of 20156011 is 11065102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11065102 = 2 ⋅5532551.

It is a cyclic number.

It is not a de Polignac number, because 20156011 - 2¹¹ = 20153963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20156021) 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, 44170 + ... + 44623.

It is an arithmetic number, because the mean of its divisors is an integer number (5061258).

Almost surely, 2^20156011 is an apocalyptic number.

20156011 is a deficient number, since it is larger than the sum of its proper divisors (89021).

20156011 is an equidigital number, since it uses as much as digits as its factorization.

20156011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89020.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 20156011 is about 4489.5446316971. The cubic root of 20156011 is about 272.1457327110.

Subtracting from 20156011 its reverse (11065102), we obtain a palindrome (9090909).

The spelling of 20156011 in words is "twenty million, one hundred fifty-six thousand, eleven".