21012221002 has 4 divisors (see below), whose sum is σ = 31518331506. Its totient is φ = 10506110500.

The previous prime is 21012220969. The next prime is 21012221047. The reversal of 21012221002 is 20012221012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20121138801 + 891082201 = 141849^2 + 29851^2 .

It is a super-3 number, since 3×21012221002³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5253055249 + ... + 5253055252.

Almost surely, 2^21012221002 is an apocalyptic number.

21012221002 is a deficient number, since it is larger than the sum of its proper divisors (10506110504).

21012221002 is a wasteful number, since it uses less digits than its factorization.

21012221002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10506110503.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21012221002 its reverse (20012221012), we get a palindrome (41024442014).

The spelling of 21012221002 in words is "twenty-one billion, twelve million, two hundred twenty-one thousand, two".