21122121001 has 16 divisors (see below), whose sum is σ = 23207184000. Its totient is φ = 19134897408.

The previous prime is 21122120993. The next prime is 21122121017. The reversal of 21122121001 is 10012122112.

It is a cyclic number.

It is not a de Polignac number, because 21122121001 - 2³ = 21122120993 is a prime.

It is a super-2 number, since 2×21122121001² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21122121091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2870475 + ... + 2877823.

It is an arithmetic number, because the mean of its divisors is an integer number (1450449000).

Almost surely, 2^21122121001 is an apocalyptic number.

It is an amenable number.

21122121001 is a deficient number, since it is larger than the sum of its proper divisors (2085062999).

21122121001 is a wasteful number, since it uses less digits than its factorization.

21122121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13968.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21122121001 its reverse (10012122112), we get a palindrome (31134243113).

The spelling of 21122121001 in words is "twenty-one billion, one hundred twenty-two million, one hundred twenty-one thousand, one".