21354665503616 has 64 divisors (see below), whose sum is σ = 43978394549760. Its totient is φ = 10317947788800.

The previous prime is 21354665503579. The next prime is 21354665503621. The reversal of 21354665503616 is 61630556645312.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1152266 + ... + 6636041.

It is an arithmetic number, because the mean of its divisors is an integer number (687162414840).

Almost surely, 2^{21354665503616} is an apocalyptic number.

It is an amenable number.

21354665503616 is an abundant number, since it is smaller than the sum of its proper divisors (22623729046144).

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

21354665503616 is an equidigital number, since it uses as much as digits as its factorization.

21354665503616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7789043 (or 7789031 counting only the distinct ones).

The product of its (nonzero) digits is 11664000, while the sum is 53.

The spelling of 21354665503616 in words is "twenty-one trillion, three hundred fifty-four billion, six hundred sixty-five million, five hundred three thousand, six hundred sixteen".