21005101131 has 8 divisors (see below), whose sum is σ = 32007773184. Its totient is φ = 12002914920.

The previous prime is 21005101063. The next prime is 21005101147. The reversal of 21005101131 is 13110150012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21005101131 - 2¹⁰ = 21005100107 is a prime.

It is a super-2 number, since 2×21005101131² (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 21005101131.

It is not an unprimeable number, because it can be changed into a prime (21005101151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 500121435 + ... + 500121476.

It is an arithmetic number, because the mean of its divisors is an integer number (4000971648).

Almost surely, 2^21005101131 is an apocalyptic number.

21005101131 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21005101131 is a deficient number, since it is larger than the sum of its proper divisors (11002672053).

21005101131 is a wasteful number, since it uses less digits than its factorization.

21005101131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000242921.

The product of its (nonzero) digits is 30, while the sum is 15.

Adding to 21005101131 its reverse (13110150012), we get a palindrome (34115251143).

The spelling of 21005101131 in words is "twenty-one billion, five million, one hundred one thousand, one hundred thirty-one".