21453516806 has 8 divisors (see below), whose sum is σ = 32181082320. Its totient is φ = 10726489368.

The previous prime is 21453516779. The next prime is 21453516827. The reversal of 21453516806 is 60861535412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12821 + ... + 207536.

It is an arithmetic number, because the mean of its divisors is an integer number (4022635290).

Almost surely, 2^21453516806 is an apocalyptic number.

21453516806 is a deficient number, since it is larger than the sum of its proper divisors (10727565514).

21453516806 is a wasteful number, since it uses less digits than its factorization.

21453516806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269038.

The product of its (nonzero) digits is 172800, while the sum is 41.

The spelling of 21453516806 in words is "twenty-one billion, four hundred fifty-three million, five hundred sixteen thousand, eight hundred six".