21001431011 has 8 divisors (see below), whose sum is σ = 23120842800. Its totient is φ = 18917051040.

The previous prime is 21001430999. The next prime is 21001431037. The reversal of 21001431011 is 11013410012.

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

It is a cyclic number.

It is not a de Polignac number, because 21001431011 - 2¹⁰ = 21001429987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001431511) 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 7 ways as a sum of consecutive naturals, for example, 8756696 + ... + 8759093.

It is an arithmetic number, because the mean of its divisors is an integer number (2890105350).

Almost surely, 2^21001431011 is an apocalyptic number.

21001431011 is a deficient number, since it is larger than the sum of its proper divisors (2119411789).

21001431011 is a wasteful number, since it uses less digits than its factorization.

21001431011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17515909.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21001431011 its reverse (11013410012), we get a palindrome (32014841023).

The spelling of 21001431011 in words is "twenty-one billion, one million, four hundred thirty-one thousand, eleven".