21521020002 has 32 divisors (see below), whose sum is σ = 44539588800. Its totient is φ = 6924230208.

The previous prime is 21521019977. The next prime is 21521020013. The reversal of 21521020002 is 20002012512.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 628693 + ... + 662039.

It is an arithmetic number, because the mean of its divisors is an integer number (1391862150).

Almost surely, 2^21521020002 is an apocalyptic number.

21521020002 is an abundant number, since it is smaller than the sum of its proper divisors (23018568798).

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

21521020002 is a wasteful number, since it uses less digits than its factorization.

21521020002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37090.

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 21521020002 its reverse (20002012512), we get a palindrome (41523032514).

The spelling of 21521020002 in words is "twenty-one billion, five hundred twenty-one million, twenty thousand, two".