21011001131 has 4 divisors (see below), whose sum is σ = 22246942392. Its totient is φ = 19775059872.

The previous prime is 21011001127. The next prime is 21011001197. The reversal of 21011001131 is 13110011012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21011001131 - 2² = 21011001127 is a prime.

It is a super-2 number, since 2×21011001131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011001931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 617970605 + ... + 617970638.

It is an arithmetic number, because the mean of its divisors is an integer number (5561735598).

Almost surely, 2^21011001131 is an apocalyptic number.

21011001131 is a deficient number, since it is larger than the sum of its proper divisors (1235941261).

21011001131 is a wasteful number, since it uses less digits than its factorization.

21011001131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235941260.

The product of its (nonzero) digits is 6, while the sum is 11.

Adding to 21011001131 its reverse (13110011012), we get a palindrome (34121012143).

The spelling of 21011001131 in words is "twenty-one billion, eleven million, one thousand, one hundred thirty-one".