21154556145504 has 96 divisors (see below), whose sum is σ = 55568076931584. Its totient is φ = 7046775406080.

The previous prime is 21154556145491. The next prime is 21154556145551. The reversal of 21154556145504 is 40554165545112.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1065120534 + ... + 1065140394.

It is an arithmetic number, because the mean of its divisors is an integer number (578834134704).

Almost surely, 2^{21154556145504} is an apocalyptic number.

21154556145504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21154556145504 is an abundant number, since it is smaller than the sum of its proper divisors (34413520786080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21154556145504 is a wasteful number, since it uses less digits than its factorization.

21154556145504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26780 (or 26772 counting only the distinct ones).

The product of its (nonzero) digits is 2400000, while the sum is 48.

The spelling of 21154556145504 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred fifty-six million, one hundred forty-five thousand, five hundred four".