21020112031031 has 4 divisors (see below), whose sum is σ = 21020143268352. Its totient is φ = 21020080793712.

The previous prime is 21020112031027. The next prime is 21020112031057. The reversal of 21020112031031 is 13013021102012.

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 21020112031031 - 2² = 21020112031027 is a prime.

It is a super-2 number, since 2×21020112031031² (a number of 27 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 (21020112031081) 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, 14586551 + ... + 15962696.

It is an arithmetic number, because the mean of its divisors is an integer number (5255035817088).

Almost surely, 2^{21020112031031} is an apocalyptic number.

21020112031031 is a deficient number, since it is larger than the sum of its proper divisors (31237321).

21020112031031 is an equidigital number, since it uses as much as digits as its factorization.

21020112031031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31237320.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21020112031031 its reverse (13013021102012), we get a palindrome (34033133133043).

The spelling of 21020112031031 in words is "twenty-one trillion, twenty billion, one hundred twelve million, thirty-one thousand, thirty-one".