81961103 has 8 divisors (see below), whose sum is σ = 93726720. Its totient is φ = 70209720.

The previous prime is 81961093. The next prime is 81961111. The reversal of 81961103 is 30116918.

It is a happy number.

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

It is not a de Polignac number, because 81961103 - 2¹⁸ = 81698959 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 (81960103) 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, 15878 + ... + 20396.

It is an arithmetic number, because the mean of its divisors is an integer number (11715840).

Almost surely, 2^81961103 is an apocalyptic number.

81961103 is a deficient number, since it is larger than the sum of its proper divisors (11765617).

81961103 is a wasteful number, since it uses less digits than its factorization.

81961103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7117.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 81961103 is about 9053.2371558465. The cubic root of 81961103 is about 434.3794436893.

The spelling of 81961103 in words is "eighty-one million, nine hundred sixty-one thousand, one hundred three".