81201213 has 12 divisors (see below), whose sum is σ = 117819520. Its totient is φ = 53890056.

The previous prime is 81201191. The next prime is 81201223. The reversal of 81201213 is 31210218.

It is not a de Polignac number, because 81201213 - 2⁵ = 81201181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81201223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18223 + ... + 22236.

Almost surely, 2^81201213 is an apocalyptic number.

It is an amenable number.

81201213 is a deficient number, since it is larger than the sum of its proper divisors (36618307).

81201213 is a wasteful number, since it uses less digits than its factorization.

81201213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40688 (or 40685 counting only the distinct ones).

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

The square root of 81201213 is about 9011.1715664502. The cubic root of 81201213 is about 433.0328456577.

The spelling of 81201213 in words is "eighty-one million, two hundred one thousand, two hundred thirteen".