21000013102 has 4 divisors (see below), whose sum is σ = 31500019656. Its totient is φ = 10500006550.

The previous prime is 21000013061. The next prime is 21000013103. The reversal of 21000013102 is 20131000012.

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 (21000013103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250003274 + ... + 5250003277.

It is an arithmetic number, because the mean of its divisors is an integer number (7875004914).

Almost surely, 2^21000013102 is an apocalyptic number.

21000013102 is a deficient number, since it is larger than the sum of its proper divisors (10500006554).

21000013102 is a wasteful number, since it uses less digits than its factorization.

21000013102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500006553.

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 21000013102 its reverse (20131000012), we get a palindrome (41131013114).

The spelling of 21000013102 in words is "twenty-one billion, thirteen thousand, one hundred two".