21210101131 has 4 divisors (see below), whose sum is σ = 21236714352. Its totient is φ = 21183487912.

The previous prime is 21210101123. The next prime is 21210101137. The reversal of 21210101131 is 13110101212.

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 21210101131 - 2³ = 21210101123 is a prime.

It is a super-2 number, since 2×21210101131² (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 (21210101137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13305415 + ... + 13307008.

It is an arithmetic number, because the mean of its divisors is an integer number (5309178588).

Almost surely, 2^21210101131 is an apocalyptic number.

21210101131 is a deficient number, since it is larger than the sum of its proper divisors (26613221).

21210101131 is an equidigital number, since it uses as much as digits as its factorization.

21210101131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26613220.

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

Adding to 21210101131 its reverse (13110101212), we get a palindrome (34320202343).

The spelling of 21210101131 in words is "twenty-one billion, two hundred ten million, one hundred one thousand, one hundred thirty-one".