21011220002031 has 32 divisors (see below), whose sum is σ = 32100305172480. Its totient is φ = 11975229962496.

The previous prime is 21011220002011. The next prime is 21011220002077. The reversal of 21011220002031 is 13020002211012.

It is not a de Polignac number, because 21011220002031 - 2⁵ = 21011220001999 is a prime.

It is a super-2 number, since 2×21011220002031² (a number of 27 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 21011220002031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011220002011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23036505 + ... + 23931213.

It is an arithmetic number, because the mean of its divisors is an integer number (1003134536640).

Almost surely, 2^{21011220002031} is an apocalyptic number.

21011220002031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21011220002031 is a deficient number, since it is larger than the sum of its proper divisors (11089085170449).

21011220002031 is a wasteful number, since it uses less digits than its factorization.

21011220002031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897623.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21011220002031 its reverse (13020002211012), we get a palindrome (34031222213043).

The spelling of 21011220002031 in words is "twenty-one trillion, eleven billion, two hundred twenty million, two thousand, thirty-one".