2145121005 has 16 divisors (see below), whose sum is σ = 3512013120. Its totient is φ = 1117458048.

The previous prime is 2145121003. The next prime is 2145121007. The reversal of 2145121005 is 5001215412.

It is an interprime number because it is at equal distance from previous prime (2145121003) and next prime (2145121007).

It is not a de Polignac number, because 2145121005 - 2¹ = 2145121003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145121001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1662240 + ... + 1663529.

It is an arithmetic number, because the mean of its divisors is an integer number (219500820).

Almost surely, 2^2145121005 is an apocalyptic number.

It is an amenable number.

2145121005 is a deficient number, since it is larger than the sum of its proper divisors (1366892115).

2145121005 is a wasteful number, since it uses less digits than its factorization.

2145121005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3325820.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 2145121005 is about 46315.4510395829. The cubic root of 2145121005 is about 1289.6858408103.

Adding to 2145121005 its reverse (5001215412), we get a palindrome (7146336417).

The spelling of 2145121005 in words is "two billion, one hundred forty-five million, one hundred twenty-one thousand, five".