2145945778 has 4 divisors (see below), whose sum is σ = 3218918670. Its totient is φ = 1072972888.

The previous prime is 2145945757. The next prime is 2145945811. The reversal of 2145945778 is 8775495412.

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

It can be written as a sum of positive squares in only one way, i.e., 1537188849 + 608756929 = 39207^2 + 24673^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 536486443 + ... + 536486446.

Almost surely, 2^2145945778 is an apocalyptic number.

2145945778 is a deficient number, since it is larger than the sum of its proper divisors (1072972892).

2145945778 is a wasteful number, since it uses less digits than its factorization.

2145945778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072972891.

The product of its digits is 2822400, while the sum is 52.

The square root of 2145945778 is about 46324.3540483837. The cubic root of 2145945778 is about 1289.8511091503.

The spelling of 2145945778 in words is "two billion, one hundred forty-five million, nine hundred forty-five thousand, seven hundred seventy-eight".