21021001002 has 48 divisors (see below), whose sum is σ = 45737782272. Its totient is φ = 6977469600.

The previous prime is 21021000989. The next prime is 21021001003. The reversal of 21021001002 is 20010012012.

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 (21021001003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8940127 + ... + 8942477.

It is an arithmetic number, because the mean of its divisors is an integer number (952870464).

Almost surely, 2^21021001002 is an apocalyptic number.

21021001002 is an abundant number, since it is smaller than the sum of its proper divisors (24716781270).

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

21021001002 is a wasteful number, since it uses less digits than its factorization.

21021001002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4243 (or 4240 counting only the distinct ones).

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

Adding to 21021001002 its reverse (20010012012), we get a palindrome (41031013014).

The spelling of 21021001002 in words is "twenty-one billion, twenty-one million, one thousand, two".