21112002 has 50 divisors (see below), whose sum is σ = 49934643. Its totient is φ = 6666948.

The previous prime is 21111991. The next prime is 21112009. The reversal of 21112002 is 20021112.

It can be written as a sum of positive squares in only one way, i.e., 10556001 + 10556001 = 3249^2 + 3249^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3249.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21112009) by changing a digit.

It is a polite number, since it can be written in 24 ways as a sum of consecutive naturals, for example, 1111149 + ... + 1111167.

Almost surely, 2^21112002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21112002

21112002 is an abundant number, since it is smaller than the sum of its proper divisors (28822641).

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

21112002 is an frugal number, since it uses more digits than its factorization.

21112002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 24 counting only the distinct ones).

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

The square root of 21112002 is about 4594.7798641502. The cubic root of 21112002 is about 276.3820323929.

Adding to 21112002 its reverse (20021112), we get a palindrome (41133114).

The spelling of 21112002 in words is "twenty-one million, one hundred twelve thousand, two".