2145408089221 has 4 divisors (see below), whose sum is σ = 2145748582444. Its totient is φ = 2145067596000.

The previous prime is 2145408089203. The next prime is 2145408089243. The reversal of 2145408089221 is 1229808045412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1468910064196 + 676498025025 = 1211986^2 + 822495^2 .

It is a cyclic number.

It is not a de Polignac number, because 2145408089221 - 2²⁵ = 2145374534789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145408089021) 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, 170237160 + ... + 170249761.

It is an arithmetic number, because the mean of its divisors is an integer number (536437145611).

Almost surely, 2^{2145408089221} is an apocalyptic number.

It is an amenable number.

2145408089221 is a deficient number, since it is larger than the sum of its proper divisors (340493223).

2145408089221 is an equidigital number, since it uses as much as digits as its factorization.

2145408089221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340493222.

The product of its (nonzero) digits is 368640, while the sum is 46.

The spelling of 2145408089221 in words is "two trillion, one hundred forty-five billion, four hundred eight million, eighty-nine thousand, two hundred twenty-one".