21243323031 has 16 divisors (see below), whose sum is σ = 32691283968. Its totient is φ = 12018852000.

The previous prime is 21243322987. The next prime is 21243323039. The reversal of 21243323031 is 13032334212.

It is not a de Polignac number, because 21243323031 - 2⁶ = 21243322967 is a prime.

It is a super-2 number, since 2×21243323031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21243322992 and 21243323010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243323039) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5005735 + ... + 5009976.

It is an arithmetic number, because the mean of its divisors is an integer number (2043205248).

Almost surely, 2^21243323031 is an apocalyptic number.

21243323031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21243323031 is a deficient number, since it is larger than the sum of its proper divisors (11447960937).

21243323031 is a wasteful number, since it uses less digits than its factorization.

21243323031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10015822.

The product of its (nonzero) digits is 2592, while the sum is 24.

Adding to 21243323031 its reverse (13032334212), we get a palindrome (34275657243).

The spelling of 21243323031 in words is "twenty-one billion, two hundred forty-three million, three hundred twenty-three thousand, thirty-one".