21085284801 has 16 divisors (see below), whose sum is σ = 32132016000. Its totient is φ = 12047962368.

The previous prime is 21085284793. The next prime is 21085284851. The reversal of 21085284801 is 10848258012.

It is not a de Polignac number, because 21085284801 - 2³ = 21085284793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21085284801.

It is not an unprimeable number, because it can be changed into a prime (21085284851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 541225 + ... + 578873.

It is an arithmetic number, because the mean of its divisors is an integer number (2008251000).

Almost surely, 2^21085284801 is an apocalyptic number.

21085284801 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21085284801 is a deficient number, since it is larger than the sum of its proper divisors (11046731199).

21085284801 is a wasteful number, since it uses less digits than its factorization.

21085284801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64328.

The product of its (nonzero) digits is 40960, while the sum is 39.

The spelling of 21085284801 in words is "twenty-one billion, eighty-five million, two hundred eighty-four thousand, eight hundred one".