21101001031 has 4 divisors (see below), whose sum is σ = 23019273864. Its totient is φ = 19182728200.

The previous prime is 21101001017. The next prime is 21101001037. The reversal of 21101001031 is 13010010112.

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 21101001031 - 2¹¹ = 21100998983 is a prime.

It is a super-2 number, since 2×21101001031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101000999 and 21101001017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101001037) 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, 959136400 + ... + 959136421.

It is an arithmetic number, because the mean of its divisors is an integer number (5754818466).

Almost surely, 2^21101001031 is an apocalyptic number.

21101001031 is a deficient number, since it is larger than the sum of its proper divisors (1918272833).

21101001031 is a wasteful number, since it uses less digits than its factorization.

21101001031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1918272832.

The product of its (nonzero) digits is 6, while the sum is 10.

Adding to 21101001031 its reverse (13010010112), we get a palindrome (34111011143).

The spelling of 21101001031 in words is "twenty-one billion, one hundred one million, one thousand, thirty-one".