21223223731 has 2 divisors, whose sum is σ = 21223223732. Its totient is φ = 21223223730.

The previous prime is 21223223713. The next prime is 21223223741. The reversal of 21223223731 is 13732232212.

Together with previous prime (21223223713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21223223731 - 2¹³ = 21223215539 is a prime.

It is a super-2 number, since 2×21223223731² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21223223731.

It is not a weakly prime, because it can be changed into another prime (21223223741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611611865 + 10611611866.

It is an arithmetic number, because the mean of its divisors is an integer number (10611611866).

Almost surely, 2^21223223731 is an apocalyptic number.

21223223731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223223731 is an equidigital number, since it uses as much as digits as its factorization.

21223223731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 28.

Adding to 21223223731 its reverse (13732232212), we get a palindrome (34955455943).

The spelling of 21223223731 in words is "twenty-one billion, two hundred twenty-three million, two hundred twenty-three thousand, seven hundred thirty-one".