21313432031 has 4 divisors (see below), whose sum is σ = 21715572312. Its totient is φ = 20911291752.

The previous prime is 21313432027. The next prime is 21313432037. The reversal of 21313432031 is 13023431312.

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 21313432031 - 2² = 21313432027 is a prime.

It is a super-2 number, since 2×21313432031² (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 = 21313431988 and 21313432006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313432037) 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, 201070061 + ... + 201070166.

It is an arithmetic number, because the mean of its divisors is an integer number (5428893078).

Almost surely, 2^21313432031 is an apocalyptic number.

21313432031 is a deficient number, since it is larger than the sum of its proper divisors (402140281).

21313432031 is an equidigital number, since it uses as much as digits as its factorization.

21313432031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402140280.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21313432031 its reverse (13023431312), we get a palindrome (34336863343).

The spelling of 21313432031 in words is "twenty-one billion, three hundred thirteen million, four hundred thirty-two thousand, thirty-one".