21002012102 has 16 divisors (see below), whose sum is σ = 33165126000. Its totient is φ = 9947105280.

The previous prime is 21002012099. The next prime is 21002012107. The reversal of 21002012102 is 20121020012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002012107) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 332774 + ... + 390822.

It is an arithmetic number, because the mean of its divisors is an integer number (2072820375).

Almost surely, 2^21002012102 is an apocalyptic number.

21002012102 is a deficient number, since it is larger than the sum of its proper divisors (12163113898).

21002012102 is a wasteful number, since it uses less digits than its factorization.

21002012102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67591.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21002012102 its reverse (20121020012), we get a palindrome (41123032114).

The spelling of 21002012102 in words is "twenty-one billion, two million, twelve thousand, one hundred two".