2051155021 has 4 divisors (see below), whose sum is σ = 2117321344. Its totient is φ = 1984988700.

The previous prime is 2051155003. The next prime is 2051155027. The reversal of 2051155021 is 1205511502.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-2051155021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2051154983 and 2051155001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2051155027) 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, 33083115 + ... + 33083176.

It is an arithmetic number, because the mean of its divisors is an integer number (529330336).

Almost surely, 2^2051155021 is an apocalyptic number.

It is an amenable number.

2051155021 is a deficient number, since it is larger than the sum of its proper divisors (66166323).

2051155021 is an equidigital number, since it uses as much as digits as its factorization.

2051155021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66166322.

The product of its (nonzero) digits is 500, while the sum is 22.

The square root of 2051155021 is about 45289.6789677295. The cubic root of 2051155021 is about 1270.5726272564.

Adding to 2051155021 its reverse (1205511502), we get a palindrome (3256666523).

The spelling of 2051155021 in words is "two billion, fifty-one million, one hundred fifty-five thousand, twenty-one".