2145637281 has 4 divisors (see below), whose sum is σ = 2860849712. Its totient is φ = 1430424852.

The previous prime is 2145637261. The next prime is 2145637283. The reversal of 2145637281 is 1827365412.

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 not a de Polignac number, because 2145637281 - 2¹⁰ = 2145636257 is a prime.

It is a super-2 number, since 2×2145637281² = 9207518683234145922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2145637283) 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, 357606211 + ... + 357606216.

It is an arithmetic number, because the mean of its divisors is an integer number (715212428).

Almost surely, 2^2145637281 is an apocalyptic number.

It is an amenable number.

2145637281 is a deficient number, since it is larger than the sum of its proper divisors (715212431).

2145637281 is an equidigital number, since it uses as much as digits as its factorization.

2145637281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715212430.

The product of its digits is 80640, while the sum is 39.

The square root of 2145637281 is about 46321.0241790917. The cubic root of 2145637281 is about 1289.7892973576.

The spelling of 2145637281 in words is "two billion, one hundred forty-five million, six hundred thirty-seven thousand, two hundred eighty-one".