21813812002 has 4 divisors (see below), whose sum is σ = 32720718006. Its totient is φ = 10906906000.

The previous prime is 21813811969. The next prime is 21813812029. The reversal of 21813812002 is 20021831812.

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., 21806133561 + 7678441 = 147669^2 + 2771^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5453452999 + ... + 5453453002.

Almost surely, 2^21813812002 is an apocalyptic number.

21813812002 is a deficient number, since it is larger than the sum of its proper divisors (10906906004).

21813812002 is a wasteful number, since it uses less digits than its factorization.

21813812002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10906906003.

The product of its (nonzero) digits is 1536, while the sum is 28.

It can be divided in two parts, 2181 and 3812002, that added together give a palindrome (3814183).

The spelling of 21813812002 in words is "twenty-one billion, eight hundred thirteen million, eight hundred twelve thousand, two".