21101021131 has 4 divisors (see below), whose sum is σ = 21781699264. Its totient is φ = 20420343000.

The previous prime is 21101021047. The next prime is 21101021147. The reversal of 21101021131 is 13112010112.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21101021131 - 2¹¹ = 21101019083 is a prime.

It is a super-2 number, since 2×21101021131² (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 (21101021531) 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, 340339020 + ... + 340339081.

It is an arithmetic number, because the mean of its divisors is an integer number (5445424816).

Almost surely, 2^21101021131 is an apocalyptic number.

21101021131 is a deficient number, since it is larger than the sum of its proper divisors (680678133).

21101021131 is an equidigital number, since it uses as much as digits as its factorization.

21101021131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680678132.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21101021131 its reverse (13112010112), we get a palindrome (34213031243).

The spelling of 21101021131 in words is "twenty-one billion, one hundred one million, twenty-one thousand, one hundred thirty-one".