81000302010021 has 48 divisors (see below), whose sum is σ = 117867974515200. Its totient is φ = 53600764310304.

The previous prime is 81000302010013. The next prime is 81000302010029. The reversal of 81000302010021 is 12001020300018.

It is an interprime number because it is at equal distance from previous prime (81000302010013) and next prime (81000302010029).

It is not a de Polignac number, because 81000302010021 - 2³ = 81000302010013 is a prime.

It is a super-2 number, since 2×81000302010021² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81000302009976 and 81000302010003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81000302010029) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3949875250 + ... + 3949895756.

It is an arithmetic number, because the mean of its divisors is an integer number (2455582802400).

Almost surely, 2^{81000302010021} is an apocalyptic number.

It is an amenable number.

81000302010021 is a deficient number, since it is larger than the sum of its proper divisors (36867672505179).

81000302010021 is a wasteful number, since it uses less digits than its factorization.

81000302010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24278 (or 24275 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 81000302010021 its reverse (12001020300018), we get a palindrome (93001322310039).

The spelling of 81000302010021 in words is "eighty-one trillion, three hundred two million, ten thousand, twenty-one".