21020021102 has 4 divisors (see below), whose sum is σ = 31530031656. Its totient is φ = 10510010550.

The previous prime is 21020021101. The next prime is 21020021131. The reversal of 21020021102 is 20112002012.

It is a happy number.

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 (21020021101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255005274 + ... + 5255005277.

It is an arithmetic number, because the mean of its divisors is an integer number (7882507914).

Almost surely, 2^21020021102 is an apocalyptic number.

21020021102 is a deficient number, since it is larger than the sum of its proper divisors (10510010554).

21020021102 is a wasteful number, since it uses less digits than its factorization.

21020021102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10510010553.

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

Adding to 21020021102 its reverse (20112002012), we get a palindrome (41132023114).

The spelling of 21020021102 in words is "twenty-one billion, twenty million, twenty-one thousand, one hundred two".