21221220031 has 8 divisors (see below), whose sum is σ = 23303737728. Its totient is φ = 19164255000.

The previous prime is 21221220029. The next prime is 21221220073. The reversal of 21221220031 is 13002212212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21221220031 - 2¹ = 21221220029 is a prime.

It is a super-2 number, since 2×21221220031² (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 = 21221219987 and 21221220014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221220011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6386425 + ... + 6389746.

It is an arithmetic number, because the mean of its divisors is an integer number (2912967216).

Almost surely, 2^21221220031 is an apocalyptic number.

21221220031 is a deficient number, since it is larger than the sum of its proper divisors (2082517697).

21221220031 is a wasteful number, since it uses less digits than its factorization.

21221220031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12776333.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21221220031 its reverse (13002212212), we get a palindrome (34223432243).

The spelling of 21221220031 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, thirty-one".