81741945 has 16 divisors (see below), whose sum is σ = 132630912. Its totient is φ = 42981120.

The previous prime is 81741941. The next prime is 81741949. The reversal of 81741945 is 54914718.

It is an interprime number because it is at equal distance from previous prime (81741941) and next prime (81741949).

It is not a de Polignac number, because 81741945 - 2² = 81741941 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81741941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37312 + ... + 39441.

It is an arithmetic number, because the mean of its divisors is an integer number (8289432).

Almost surely, 2^81741945 is an apocalyptic number.

It is an amenable number.

81741945 is a deficient number, since it is larger than the sum of its proper divisors (50888967).

81741945 is a wasteful number, since it uses less digits than its factorization.

81741945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76832.

The product of its digits is 40320, while the sum is 39.

The square root of 81741945 is about 9041.1252065216. The cubic root of 81741945 is about 433.9919317945.

The spelling of 81741945 in words is "eighty-one million, seven hundred forty-one thousand, nine hundred forty-five".