21202020001000 has 64 divisors (see below), whose sum is σ = 49620468465360. Its totient is φ = 8479484640000.

The previous prime is 21202020000919. The next prime is 21202020001067. The reversal of 21202020001000 is 10002020212.

It can be written as a sum of positive squares in 8 ways, for example, as 360316324 + 21201659684676 = 18982^2 + 4604526^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4770010 + ... + 8071990.

Almost surely, 2^{21202020001000} is an apocalyptic number.

21202020001000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202020001000 is an abundant number, since it is smaller than the sum of its proper divisors (28418448464360).

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

21202020001000 is a wasteful number, since it uses less digits than its factorization.

21202020001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3308423 (or 3308409 counting only the distinct ones).

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

Adding to 21202020001000 its reverse (10002020212), we get a palindrome (21212022021212).

The spelling of 21202020001000 in words is "twenty-one trillion, two hundred two billion, twenty million, one thousand".