21123655420245 has 32 divisors (see below), whose sum is σ = 38930255413248. Its totient is φ = 9580492531008.

The previous prime is 21123655420237. The next prime is 21123655420277. The reversal of 21123655420245 is 54202455632112.

It is not a de Polignac number, because 21123655420245 - 2³ = 21123655420237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123655420197 and 21123655420206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 792024739 + ... + 792051408.

It is an arithmetic number, because the mean of its divisors is an integer number (1216570481664).

Almost surely, 2^{21123655420245} is an apocalyptic number.

It is an amenable number.

21123655420245 is a deficient number, since it is larger than the sum of its proper divisors (17806599993003).

21123655420245 is a wasteful number, since it uses less digits than its factorization.

21123655420245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1584076289.

The product of its (nonzero) digits is 576000, while the sum is 42.

The spelling of 21123655420245 in words is "twenty-one trillion, one hundred twenty-three billion, six hundred fifty-five million, four hundred twenty thousand, two hundred forty-five".