81321301 has 4 divisors (see below), whose sum is σ = 83519212. Its totient is φ = 79123392.

The previous prime is 81321287. The next prime is 81321313. The reversal of 81321301 is 10312318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10312318 = 2 ⋅5156159.

It can be written as a sum of positive squares in 2 ways, for example, as 73977201 + 7344100 = 8601^2 + 2710^2 .

It is a cyclic number.

It is not a de Polignac number, because 81321301 - 2⁵ = 81321269 is a prime.

It is a super-2 number, since 2×81321301² = 13226307992665202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81321371) 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, 1098900 + ... + 1098973.

It is an arithmetic number, because the mean of its divisors is an integer number (20879803).

Almost surely, 2^81321301 is an apocalyptic number.

It is an amenable number.

81321301 is a deficient number, since it is larger than the sum of its proper divisors (2197911).

81321301 is a wasteful number, since it uses less digits than its factorization.

81321301 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2197910.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 81321301 is about 9017.8323892164. The cubic root of 81321301 is about 433.2462104270.

Adding to 81321301 its reverse (10312318), we get a palindrome (91633619).

The spelling of 81321301 in words is "eighty-one million, three hundred twenty-one thousand, three hundred one".