21011030021031 has 4 divisors (see below), whose sum is σ = 28014706694712. Its totient is φ = 14007353347352.

The previous prime is 21011030021027. The next prime is 21011030021057. The reversal of 21011030021031 is 13012003011012.

It is a happy number.

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 21011030021031 - 2² = 21011030021027 is a prime.

It is a super-2 number, since 2×21011030021031² (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 21011030021031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011030021011) 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, 3501838336836 + ... + 3501838336841.

It is an arithmetic number, because the mean of its divisors is an integer number (7003676673678).

Almost surely, 2^{21011030021031} is an apocalyptic number.

21011030021031 is a deficient number, since it is larger than the sum of its proper divisors (7003676673681).

21011030021031 is an equidigital number, since it uses as much as digits as its factorization.

21011030021031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003676673680.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21011030021031 its reverse (13012003011012), we get a palindrome (34023033032043).

The spelling of 21011030021031 in words is "twenty-one trillion, eleven billion, thirty million, twenty-one thousand, thirty-one".