21220042031 has 12 divisors (see below), whose sum is σ = 21574183080. Its totient is φ = 20871279600.

The previous prime is 21220042027. The next prime is 21220042037. The reversal of 21220042031 is 13024002212.

It is not a de Polignac number, because 21220042031 - 2² = 21220042027 is a prime.

It is a super-2 number, since 2×21220042031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220042037) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1570856 + ... + 1584306.

It is an arithmetic number, because the mean of its divisors is an integer number (1797848590).

Almost surely, 2^21220042031 is an apocalyptic number.

21220042031 is a deficient number, since it is larger than the sum of its proper divisors (354141049).

21220042031 is an equidigital number, since it uses as much as digits as its factorization.

21220042031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13846 (or 13763 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21220042031 its reverse (13024002212), we get a palindrome (34244044243).

The spelling of 21220042031 in words is "twenty-one billion, two hundred twenty million, forty-two thousand, thirty-one".