81200161 has 8 divisors (see below), whose sum is σ = 94775040. Its totient is φ = 68119008.

The previous prime is 81200137. The next prime is 81200173. The reversal of 81200161 is 16100218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81200161 - 2¹¹ = 81198113 is a prime.

It is a super-2 number, since 2×81200161² = 13186932292851842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81230161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123076 + ... + 123733.

It is an arithmetic number, because the mean of its divisors is an integer number (11846880).

Almost surely, 2^81200161 is an apocalyptic number.

It is an amenable number.

81200161 is a deficient number, since it is larger than the sum of its proper divisors (13574879).

81200161 is a wasteful number, since it uses less digits than its factorization.

81200161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246863.

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 81200161 is about 9011.1131942729. The cubic root of 81200161 is about 433.0309756014.

Adding to 81200161 its reverse (16100218), we get a palindrome (97300379).

The spelling of 81200161 in words is "eighty-one million, two hundred thousand, one hundred sixty-one".