21203412102 has 48 divisors (see below), whose sum is σ = 48372480000. Its totient is φ = 6693900912.

The previous prime is 21203412077. The next prime is 21203412103. The reversal of 21203412102 is 20121430212.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203412103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1634799 + ... + 1647717.

It is an arithmetic number, because the mean of its divisors is an integer number (1007760000).

Almost surely, 2^21203412102 is an apocalyptic number.

21203412102 is an abundant number, since it is smaller than the sum of its proper divisors (27169067898).

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

21203412102 is a wasteful number, since it uses less digits than its factorization.

21203412102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17745 (or 17742 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21203412102 its reverse (20121430212), we get a palindrome (41324842314).

The spelling of 21203412102 in words is "twenty-one billion, two hundred three million, four hundred twelve thousand, one hundred two".