21102310031 has 4 divisors (see below), whose sum is σ = 23020701864. Its totient is φ = 19183918200.

The previous prime is 21102310013. The next prime is 21102310067. The reversal of 21102310031 is 13001320112.

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 21102310031 - 2¹⁸ = 21102047887 is a prime.

It is a super-2 number, since 2×21102310031² (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 = 21102309988 and 21102310015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102310631) 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, 959195900 + ... + 959195921.

It is an arithmetic number, because the mean of its divisors is an integer number (5755175466).

Almost surely, 2^21102310031 is an apocalyptic number.

21102310031 is a deficient number, since it is larger than the sum of its proper divisors (1918391833).

21102310031 is a wasteful number, since it uses less digits than its factorization.

21102310031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1918391832.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21102310031 its reverse (13001320112), we get a palindrome (34103630143).

It can be divided in two parts, 21102 and 310031, that added together give a palindrome (331133).

The spelling of 21102310031 in words is "twenty-one billion, one hundred two million, three hundred ten thousand, thirty-one".