81202211 has 4 divisors (see below), whose sum is σ = 81651024. Its totient is φ = 80753400.

The previous prime is 81202171. The next prime is 81202243. The reversal of 81202211 is 11220218.

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 81202211 - 2²² = 77007907 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81202211.

It is not an unprimeable number, because it can be changed into a prime (81202111) 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, 224135 + ... + 224496.

It is an arithmetic number, because the mean of its divisors is an integer number (20412756).

Almost surely, 2^81202211 is an apocalyptic number.

81202211 is a deficient number, since it is larger than the sum of its proper divisors (448813).

81202211 is a wasteful number, since it uses less digits than its factorization.

81202211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448812.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 81202211 is about 9011.2269419874. The cubic root of 81202211 is about 433.0346197076.

Adding to 81202211 its reverse (11220218), we get a palindrome (92422429).

The spelling of 81202211 in words is "eighty-one million, two hundred two thousand, two hundred eleven".