2151723123 has 40 divisors (see below), whose sum is σ = 3601337520. Its totient is φ = 1268809920.

The previous prime is 2151723109. The next prime is 2151723131. The reversal of 2151723123 is 3213271512.

2151723123 is a `hidden beast` number, since 2 + 1 + 517 + 23 + 123 = 666.

It is not a de Polignac number, because 2151723123 - 2¹⁰ = 2151722099 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2151723143) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 333 + ... + 65601.

It is an arithmetic number, because the mean of its divisors is an integer number (90033438).

Almost surely, 2^2151723123 is an apocalyptic number.

2151723123 is a deficient number, since it is larger than the sum of its proper divisors (1449614397).

2151723123 is a wasteful number, since it uses less digits than its factorization.

2151723123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65329 (or 65320 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 2151723123 is about 46386.6696692056. The cubic root of 2151723123 is about 1291.0075902901.

Adding to 2151723123 its reverse (3213271512), we get a palindrome (5364994635).

The spelling of 2151723123 in words is "two billion, one hundred fifty-one million, seven hundred twenty-three thousand, one hundred twenty-three".