21001520214 has 128 divisors (see below), whose sum is σ = 51137740800. Its totient is φ = 6360145920.

The previous prime is 21001520209. The next prime is 21001520233. The reversal of 21001520214 is 41202510012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16419627 + ... + 16420905.

It is an arithmetic number, because the mean of its divisors is an integer number (399513600).

Almost surely, 2^21001520214 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21001520214, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25568870400).

21001520214 is an abundant number, since it is smaller than the sum of its proper divisors (30136220586).

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

21001520214 is a wasteful number, since it uses less digits than its factorization.

21001520214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1915 (or 1909 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The spelling of 21001520214 in words is "twenty-one billion, one million, five hundred twenty thousand, two hundred fourteen".