21230212123 has 8 divisors (see below), whose sum is σ = 22277030400. Its totient is φ = 20193707688.

The previous prime is 21230212103. The next prime is 21230212139. The reversal of 21230212123 is 32121203212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230212123 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21230212123.

It is not an unprimeable number, because it can be changed into a prime (21230212103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2574243 + ... + 2582476.

It is an arithmetic number, because the mean of its divisors is an integer number (2784628800).

Almost surely, 2^21230212123 is an apocalyptic number.

21230212123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21230212123 is a deficient number, since it is larger than the sum of its proper divisors (1046818277).

21230212123 is a wasteful number, since it uses less digits than its factorization.

21230212123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5156921.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21230212123 its reverse (32121203212), we get a palindrome (53351415335).

The spelling of 21230212123 in words is "twenty-one billion, two hundred thirty million, two hundred twelve thousand, one hundred twenty-three".