21000122002 has 8 divisors (see below), whose sum is σ = 32586396300. Its totient is φ = 10137989904.

The previous prime is 21000121997. The next prime is 21000122027. The reversal of 21000122002 is 20022100012.

It can be written as a sum of positive squares in 2 ways, for example, as 19971059761 + 1029062241 = 141319^2 + 32079^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21000122002.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181035477 + ... + 181035592.

Almost surely, 2^21000122002 is an apocalyptic number.

21000122002 is a deficient number, since it is larger than the sum of its proper divisors (11586274298).

21000122002 is a wasteful number, since it uses less digits than its factorization.

21000122002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362071100.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21000122002 its reverse (20022100012), we get a palindrome (41022222014).

It can be divided in two parts, 2100012 and 2002, that multiplied together give a palindrome (4204224024).

The spelling of 21000122002 in words is "twenty-one billion, one hundred twenty-two thousand, two".