20021000031 has 12 divisors (see below), whose sum is σ = 28922129808. Its totient is φ = 13345991424.

The previous prime is 20020999951. The next prime is 20021000047. The reversal of 20021000031 is 13000012002.

It is a happy number.

It is not a de Polignac number, because 20021000031 - 2¹⁰ = 20020999007 is a prime.

It is a super-2 number, since 2×20021000031² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20020999977 and 20021000022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021000431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12715 + ... + 200508.

It is an arithmetic number, because the mean of its divisors is an integer number (2410177484).

Almost surely, 2^20021000031 is an apocalyptic number.

20021000031 is a deficient number, since it is larger than the sum of its proper divisors (8901129777).

20021000031 is a wasteful number, since it uses less digits than its factorization.

20021000031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223662 (or 223659 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 20021000031 its reverse (13000012002), we get a palindrome (33021012033).

The spelling of 20021000031 in words is "twenty billion, twenty-one million, thirty-one", and thus it is an aban number and an uban number.