21021002106 has 32 divisors (see below), whose sum is σ = 45344819520. Its totient is φ = 6458169984.

The previous prime is 21021002087. The next prime is 21021002111. The reversal of 21021002106 is 60120012012.

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, 153075 + ... + 255878.

It is an arithmetic number, because the mean of its divisors is an integer number (1417025610).

Almost surely, 2^21021002106 is an apocalyptic number.

21021002106 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21021002106 is an abundant number, since it is smaller than the sum of its proper divisors (24323817414).

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

21021002106 is a wasteful number, since it uses less digits than its factorization.

21021002106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409630.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21021002106 its reverse (60120012012), we get a palindrome (81141014118).

The spelling of 21021002106 in words is "twenty-one billion, twenty-one million, two thousand, one hundred six".