2123154421015 has 4 divisors (see below), whose sum is σ = 2547785305224. Its totient is φ = 1698523536808.

The previous prime is 2123154420991. The next prime is 2123154421097. The reversal of 2123154421015 is 5101244513212.

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

It is a cyclic number.

It is not a de Polignac number, because 2123154421015 - 2⁷ = 2123154420887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212315442097 + ... + 212315442106.

It is an arithmetic number, because the mean of its divisors is an integer number (636946326306).

Almost surely, 2^{2123154421015} is an apocalyptic number.

2123154421015 is a deficient number, since it is larger than the sum of its proper divisors (424630884209).

2123154421015 is an equidigital number, since it uses as much as digits as its factorization.

2123154421015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424630884208.

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 2123154421015 its reverse (5101244513212), we get a palindrome (7224398934227).

The spelling of 2123154421015 in words is "two trillion, one hundred twenty-three billion, one hundred fifty-four million, four hundred twenty-one thousand, fifteen".