21311012102 has 4 divisors (see below), whose sum is σ = 31966518156. Its totient is φ = 10655506050.

The previous prime is 21311012101. The next prime is 21311012159. The reversal of 21311012102 is 20121011312.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311012101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5327753024 + ... + 5327753027.

It is an arithmetic number, because the mean of its divisors is an integer number (7991629539).

Almost surely, 2^21311012102 is an apocalyptic number.

21311012102 is a deficient number, since it is larger than the sum of its proper divisors (10655506054).

21311012102 is a wasteful number, since it uses less digits than its factorization.

21311012102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10655506053.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21311012102 its reverse (20121011312), we get a palindrome (41432023414).

The spelling of 21311012102 in words is "twenty-one billion, three hundred eleven million, twelve thousand, one hundred two".