23405142121 has 4 divisors (see below), whose sum is σ = 23456357332. Its totient is φ = 23353926912.

The previous prime is 23405142113. The next prime is 23405142151. The reversal of 23405142121 is 12124150432.

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 8143257600 + 15261884521 = 90240^2 + 123539^2 .

It is a cyclic number.

It is not a de Polignac number, because 23405142121 - 2³ = 23405142113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23405142151) 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, 25606920 + ... + 25607833.

It is an arithmetic number, because the mean of its divisors is an integer number (5864089333).

Almost surely, 2^23405142121 is an apocalyptic number.

It is an amenable number.

23405142121 is a deficient number, since it is larger than the sum of its proper divisors (51215211).

23405142121 is an equidigital number, since it uses as much as digits as its factorization.

23405142121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51215210.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 23405142121 its reverse (12124150432), we get a palindrome (35529292553).

The spelling of 23405142121 in words is "twenty-three billion, four hundred five million, one hundred forty-two thousand, one hundred twenty-one".