21023212123 has 8 divisors (see below), whose sum is σ = 22644919296. Its totient is φ = 19460476200.

The previous prime is 21023212103. The next prime is 21023212139. The reversal of 21023212123 is 32121232012.

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

It is a cyclic number.

It is not a de Polignac number, because 21023212123 - 2⁹ = 21023211611 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 21023212123.

It is not an unprimeable number, because it can be changed into a prime (21023212103) 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, 14742073 + ... + 14743498.

It is an arithmetic number, because the mean of its divisors is an integer number (2830614912).

Almost surely, 2^21023212123 is an apocalyptic number.

21023212123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21023212123 is a deficient number, since it is larger than the sum of its proper divisors (1621707173).

21023212123 is a wasteful number, since it uses less digits than its factorization.

21023212123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29485625.

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

Adding to 21023212123 its reverse (32121232012), we get a palindrome (53144444135).

The spelling of 21023212123 in words is "twenty-one billion, twenty-three million, two hundred twelve thousand, one hundred twenty-three".