21216223654123 has 48 divisors (see below), whose sum is σ = 23478627444480. Its totient is φ = 19132572900672.

The previous prime is 21216223654121. The next prime is 21216223654141. The reversal of 21216223654123 is 32145632261212.

It is not a de Polignac number, because 21216223654123 - 2¹ = 21216223654121 is a prime.

It is a super-2 number, since 2×21216223654123² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21216223654121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1469565661 + ... + 1469580097.

It is an arithmetic number, because the mean of its divisors is an integer number (489138071760).

Almost surely, 2^{21216223654123} is an apocalyptic number.

21216223654123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21216223654123 is a deficient number, since it is larger than the sum of its proper divisors (2262403790357).

21216223654123 is a wasteful number, since it uses less digits than its factorization.

21216223654123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15344 (or 15325 counting only the distinct ones).

The product of its digits is 207360, while the sum is 40.

The spelling of 21216223654123 in words is "twenty-one trillion, two hundred sixteen billion, two hundred twenty-three million, six hundred fifty-four thousand, one hundred twenty-three".