21030200123 has 4 divisors (see below), whose sum is σ = 21057406848. Its totient is φ = 21002993400.

The previous prime is 21030200101. The next prime is 21030200153. The reversal of 21030200123 is 32100203012.

It is a happy number.

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 21030200123 - 2²⁰ = 21029151547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21030200098 and 21030200107.

It is not an unprimeable number, because it can be changed into a prime (21030200153) 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, 13602203 + ... + 13603748.

It is an arithmetic number, because the mean of its divisors is an integer number (5264351712).

Almost surely, 2^21030200123 is an apocalyptic number.

21030200123 is a deficient number, since it is larger than the sum of its proper divisors (27206725).

21030200123 is an equidigital number, since it uses as much as digits as its factorization.

21030200123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27206724.

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 21030200123 its reverse (32100203012), we get a palindrome (53130403135).

The spelling of 21030200123 in words is "twenty-one billion, thirty million, two hundred thousand, one hundred twenty-three".