123310030021 has 4 divisors (see below), whose sum is σ = 123342750700. Its totient is φ = 123277309344.

The previous prime is 123310030007. The next prime is 123310030057. The reversal of 123310030021 is 120030013321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120030013321 = 1187 ⋅101120483.

It can be written as a sum of positive squares in 2 ways, for example, as 100307757796 + 23002272225 = 316714^2 + 151665^2 .

It is a cyclic number.

It is not a de Polignac number, because 123310030021 - 2²⁷ = 123175812293 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123310029977 and 123310030004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123310030061) 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, 16354686 + ... + 16362223.

It is an arithmetic number, because the mean of its divisors is an integer number (30835687675).

Almost surely, 2^123310030021 is an apocalyptic number.

It is an amenable number.

123310030021 is a deficient number, since it is larger than the sum of its proper divisors (32720679).

123310030021 is an equidigital number, since it uses as much as digits as its factorization.

123310030021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32720678.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 123310030021 its reverse (120030013321), we get a palindrome (243340043342).

The spelling of 123310030021 in words is "one hundred twenty-three billion, three hundred ten million, thirty thousand, twenty-one".