2154281345 has 4 divisors (see below), whose sum is σ = 2585137620. Its totient is φ = 1723425072.

The previous prime is 2154281329. The next prime is 2154281369. The reversal of 2154281345 is 5431824512.

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 1096470769 + 1057810576 = 33113^2 + 32524^2 .

It is a cyclic number.

It is not a de Polignac number, because 2154281345 - 2⁴ = 2154281329 is a prime.

It is a super-2 number, since 2×2154281345² = 9281856226830018050, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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, 215428130 + ... + 215428139.

It is an arithmetic number, because the mean of its divisors is an integer number (646284405).

Almost surely, 2^2154281345 is an apocalyptic number.

It is an amenable number.

2154281345 is a deficient number, since it is larger than the sum of its proper divisors (430856275).

2154281345 is an equidigital number, since it uses as much as digits as its factorization.

2154281345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430856274.

The product of its digits is 38400, while the sum is 35.

The square root of 2154281345 is about 46414.2364474522. The cubic root of 2154281345 is about 1291.5190216440.

The spelling of 2154281345 in words is "two billion, one hundred fifty-four million, two hundred eighty-one thousand, three hundred forty-five".