21424420031 has 4 divisors (see below), whose sum is σ = 24485051472. Its totient is φ = 18363788592.

The previous prime is 21424420019. The next prime is 21424420037. The reversal of 21424420031 is 13002442412.

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 21424420031 - 2¹⁴ = 21424403647 is a prime.

It is a super-2 number, since 2×21424420031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21424419979 and 21424420006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424420037) 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, 1530315710 + ... + 1530315723.

It is an arithmetic number, because the mean of its divisors is an integer number (6121262868).

Almost surely, 2^21424420031 is an apocalyptic number.

21424420031 is a deficient number, since it is larger than the sum of its proper divisors (3060631441).

21424420031 is an equidigital number, since it uses as much as digits as its factorization.

21424420031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3060631440.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21424420031 its reverse (13002442412), we get a palindrome (34426862443).

The spelling of 21424420031 in words is "twenty-one billion, four hundred twenty-four million, four hundred twenty thousand, thirty-one".