21021121131 has 16 divisors (see below), whose sum is σ = 28563317280. Its totient is φ = 13746620160.

The previous prime is 21021121117. The next prime is 21021121201. The reversal of 21021121131 is 13112112012.

It is not a de Polignac number, because 21021121131 - 2¹¹ = 21021119083 is a prime.

It is a super-2 number, since 2×21021121131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21021121131.

It is not an unprimeable number, because it can be changed into a prime (21021121631) 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, 875535 + ... + 899223.

It is an arithmetic number, because the mean of its divisors is an integer number (1785207330).

Almost surely, 2^21021121131 is an apocalyptic number.

21021121131 is a deficient number, since it is larger than the sum of its proper divisors (7542196149).

21021121131 is a wasteful number, since it uses less digits than its factorization.

21021121131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29326.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21021121131 its reverse (13112112012), we get a palindrome (34133233143).

The spelling of 21021121131 in words is "twenty-one billion, twenty-one million, one hundred twenty-one thousand, one hundred thirty-one".