21001001010102 has 32 divisors (see below), whose sum is σ = 46670961490560. Its totient is φ = 7000023116520.

The previous prime is 21001001010089. The next prime is 21001001010109. The reversal of 21001001010102 is 20101010010012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001001010109) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7396368 + ... + 9834035.

It is an arithmetic number, because the mean of its divisors is an integer number (1458467546580).

Almost surely, 2^{21001001010102} is an apocalyptic number.

21001001010102 is an abundant number, since it is smaller than the sum of its proper divisors (25669960480458).

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

21001001010102 is a wasteful number, since it uses less digits than its factorization.

21001001010102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17252985 (or 17252979 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21001001010102 its reverse (20101010010012), we get a palindrome (41102011020114).

The spelling of 21001001010102 in words is "twenty-one trillion, one billion, one million, ten thousand, one hundred two".