21021001201 has 4 divisors (see below), whose sum is σ = 21035489904. Its totient is φ = 21006512500.

The previous prime is 21021001193. The next prime is 21021001213. The reversal of 21021001201 is 10210012012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21021001201 - 2³ = 21021001193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021001231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7242175 + ... + 7245076.

It is an arithmetic number, because the mean of its divisors is an integer number (5258872476).

Almost surely, 2^21021001201 is an apocalyptic number.

It is an amenable number.

21021001201 is a deficient number, since it is larger than the sum of its proper divisors (14488703).

21021001201 is a wasteful number, since it uses less digits than its factorization.

21021001201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14488702.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21021001201 its reverse (10210012012), we get a palindrome (31231013213).

It can be divided in two parts, 2 and 1021001201, that multiplied together give a palindrome (2042002402).

The spelling of 21021001201 in words is "twenty-one billion, twenty-one million, one thousand, two hundred one".