21021212120123 has 8 divisors (see below), whose sum is σ = 22258017834192. Its totient is φ = 19784435719936.

The previous prime is 21021212120099. The next prime is 21021212120147. The reversal of 21021212120123 is 32102121212012.

It is an interprime number because it is at equal distance from previous prime (21021212120099) and next prime (21021212120147).

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 21021212120123 - 2¹² = 21021212116027 is a prime.

It is a super-2 number, since 2×21021212120123² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021212120095 and 21021212120104.

It is not an unprimeable number, because it can be changed into a prime (21021212120323) 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, 5843465 + ... + 8728602.

It is an arithmetic number, because the mean of its divisors is an integer number (2782252229274).

Almost surely, 2^{21021212120123} is an apocalyptic number.

21021212120123 is a deficient number, since it is larger than the sum of its proper divisors (1236805714069).

21021212120123 is a wasteful number, since it uses less digits than its factorization.

21021212120123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14656941.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21021212120123 its reverse (32102121212012), we get a palindrome (53123333332135).

It can be divided in two parts, 2102121212012 and 3, that multiplied together give a palindrome (6306363636036).

The spelling of 21021212120123 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, one hundred twenty thousand, one hundred twenty-three".