21021102 has 12 divisors (see below), whose sum is σ = 45545760. Its totient is φ = 7007028.

The previous prime is 21021101. The next prime is 21021107. The reversal of 21021102 is 20112012.

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 (21021101) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583902 + ... + 583937.

It is an arithmetic number, because the mean of its divisors is an integer number (3795480).

Almost surely, 2^21021102 is an apocalyptic number.

21021102 is an abundant number, since it is smaller than the sum of its proper divisors (24524658).

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

21021102 is a wasteful number, since it uses less digits than its factorization.

21021102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1167847 (or 1167844 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 21021102 is about 4584.8775338061. The cubic root of 21021102 is about 275.9847975243.

Adding to 21021102 its reverse (20112012), we get a palindrome (41133114).

It can be divided in two parts, 210 and 21102, that added together give a palindrome (21312).

The spelling of 21021102 in words is "twenty-one million, twenty-one thousand, one hundred two".