21154510145021 has 16 divisors (see below), whose sum is σ = 23715140275008. Its totient is φ = 18700732886400.

The previous prime is 21154510145003. The next prime is 21154510145057. The reversal of 21154510145021 is 12054101545112.

It is a cyclic number.

It is not a de Polignac number, because 21154510145021 - 2¹⁴ = 21154510128637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154510145071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14400275 + ... + 15801168.

It is an arithmetic number, because the mean of its divisors is an integer number (1482196267188).

Almost surely, 2^{21154510145021} is an apocalyptic number.

It is an amenable number.

21154510145021 is a deficient number, since it is larger than the sum of its proper divisors (2560630129987).

21154510145021 is a wasteful number, since it uses less digits than its factorization.

21154510145021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30203212.

The product of its (nonzero) digits is 8000, while the sum is 32.

The spelling of 21154510145021 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred ten million, one hundred forty-five thousand, twenty-one".