21154475516 has 12 divisors (see below), whose sum is σ = 38214536640. Its totient is φ = 10236036480.

The previous prime is 21154475501. The next prime is 21154475519. The reversal of 21154475516 is 61557445112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154475519) 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 3 ways as a sum of consecutive naturals, for example, 85300181 + ... + 85300428.

It is an arithmetic number, because the mean of its divisors is an integer number (3184544720).

Almost surely, 2^21154475516 is an apocalyptic number.

It is an amenable number.

21154475516 is a deficient number, since it is larger than the sum of its proper divisors (17060061124).

21154475516 is a wasteful number, since it uses less digits than its factorization.

21154475516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170600644 (or 170600642 counting only the distinct ones).

The product of its digits is 168000, while the sum is 41.

The spelling of 21154475516 in words is "twenty-one billion, one hundred fifty-four million, four hundred seventy-five thousand, five hundred sixteen".