2145539993 has 4 divisors (see below), whose sum is σ = 2167659060. Its totient is φ = 2123420928.

The previous prime is 2145539987. The next prime is 2145540043. The reversal of 2145539993 is 3999355412.

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 1641627289 + 503912704 = 40517^2 + 22448^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2145539993 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2145539933) 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, 11059388 + ... + 11059581.

It is an arithmetic number, because the mean of its divisors is an integer number (541914765).

Almost surely, 2^2145539993 is an apocalyptic number.

It is an amenable number.

2145539993 is a deficient number, since it is larger than the sum of its proper divisors (22119067).

2145539993 is an equidigital number, since it uses as much as digits as its factorization.

2145539993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22119066.

The product of its digits is 1312200, while the sum is 50.

The square root of 2145539993 is about 46319.9740176956. The cubic root of 2145539993 is about 1289.7698030844.

The spelling of 2145539993 in words is "two billion, one hundred forty-five million, five hundred thirty-nine thousand, nine hundred ninety-three".