21021021011001 has 32 divisors (see below), whose sum is σ = 30886409635200. Its totient is φ = 12610750592000.

The previous prime is 21021021010987. The next prime is 21021021011009. The reversal of 21021021011001 is 10011012012012.

It is not a de Polignac number, because 21021021011001 - 2²¹ = 21021018913849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21021021011009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12716491 + ... + 14274143.

It is an arithmetic number, because the mean of its divisors is an integer number (965200301100).

Almost surely, 2^{21021021011001} is an apocalyptic number.

It is an amenable number.

21021021011001 is a deficient number, since it is larger than the sum of its proper divisors (9865388624199).

21021021011001 is a wasteful number, since it uses less digits than its factorization.

21021021011001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561817.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21021021011001 its reverse (10011012012012), we get a palindrome (31032033023013).

The spelling of 21021021011001 in words is "twenty-one trillion, twenty-one billion, twenty-one million, eleven thousand, one".