21121002 has 24 divisors (see below), whose sum is σ = 52299936. Its totient is φ = 6034536.

The previous prime is 21120959. The next prime is 21121003. The reversal of 21121002 is 20012112.

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 (21121003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83688 + ... + 83939.

It is an arithmetic number, because the mean of its divisors is an integer number (2179164).

Almost surely, 2^21121002 is an apocalyptic number.

21121002 is an abundant number, since it is smaller than the sum of its proper divisors (31178934).

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

21121002 is a wasteful number, since it uses less digits than its factorization.

21121002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167642 (or 167639 counting only the distinct ones).

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

The square root of 21121002 is about 4595.7591320695. The cubic root of 21121002 is about 276.4213004975.

Adding to 21121002 its reverse (20012112), we get a palindrome (41133114).

The spelling of 21121002 in words is "twenty-one million, one hundred twenty-one thousand, two".