81072045 has 12 divisors (see below), whose sum is σ = 140524956. Its totient is φ = 43238400.

The previous prime is 81072041. The next prime is 81072049. The reversal of 81072045 is 54027018.

It is an interprime number because it is at equal distance from previous prime (81072041) and next prime (81072049).

It can be written as a sum of positive squares in 2 ways, for example, as 37234404 + 43837641 = 6102^2 + 6621^2 .

It is not a de Polignac number, because 81072045 - 2² = 81072041 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81072041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 900756 + ... + 900845.

It is an arithmetic number, because the mean of its divisors is an integer number (11710413).

Almost surely, 2^81072045 is an apocalyptic number.

It is an amenable number.

81072045 is a deficient number, since it is larger than the sum of its proper divisors (59452911).

81072045 is a wasteful number, since it uses less digits than its factorization.

81072045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801612 (or 1801609 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 81072045 is about 9004.0016103952. The cubic root of 81072045 is about 432.8031131651.

The spelling of 81072045 in words is "eighty-one million, seventy-two thousand, forty-five".