21216042645154 has 48 divisors (see below), whose sum is σ = 37815282718200. Its totient is φ = 8898097318656.

The previous prime is 21216042645143. The next prime is 21216042645221. The reversal of 21216042645154 is 45154624061212.

It can be written as a sum of positive squares in 4 ways, for example, as 21071359026025 + 144683619129 = 4590355^2 + 380373^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21216042645154.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3229819 + ... + 7270750.

Almost surely, 2^{21216042645154} is an apocalyptic number.

21216042645154 is a deficient number, since it is larger than the sum of its proper divisors (16599240073046).

21216042645154 is a wasteful number, since it uses less digits than its factorization.

21216042645154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10501027 (or 10501020 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 43.

The spelling of 21216042645154 in words is "twenty-one trillion, two hundred sixteen billion, forty-two million, six hundred forty-five thousand, one hundred fifty-four".