2020156681 has 4 divisors (see below), whose sum is σ = 2048609664. Its totient is φ = 1991703700.

The previous prime is 2020156609. The next prime is 2020156687. The reversal of 2020156681 is 1866510202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2020156681 - 2⁷ = 2020156553 is a prime.

It is a super-2 number, since 2×2020156681² = 8162066031577871522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2020156687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14226385 + ... + 14226526.

It is an arithmetic number, because the mean of its divisors is an integer number (512152416).

Almost surely, 2^2020156681 is an apocalyptic number.

It is an amenable number.

2020156681 is a deficient number, since it is larger than the sum of its proper divisors (28452983).

2020156681 is an equidigital number, since it uses as much as digits as its factorization.

2020156681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28452982.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 2020156681 is about 44946.1531279374. The cubic root of 2020156681 is about 1264.1395474387.

Adding to 2020156681 its reverse (1866510202), we get a palindrome (3886666883).

The spelling of 2020156681 in words is "two billion, twenty million, one hundred fifty-six thousand, six hundred eighty-one".