81009037 has 4 divisors (see below), whose sum is σ = 82337116. Its totient is φ = 79680960.

The previous prime is 81009031. The next prime is 81009053. The reversal of 81009037 is 73090018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73090018 = 2 ⋅36545009.

It can be written as a sum of positive squares in 2 ways, for example, as 6687396 + 74321641 = 2586^2 + 8621^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81009037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81008996 and 81009014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81009031) 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, 663948 + ... + 664069.

It is an arithmetic number, because the mean of its divisors is an integer number (20584279).

Almost surely, 2^81009037 is an apocalyptic number.

It is an amenable number.

81009037 is a deficient number, since it is larger than the sum of its proper divisors (1328079).

81009037 is a wasteful number, since it uses less digits than its factorization.

81009037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328078.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 81009037 is about 9000.5020415530. The cubic root of 81009037 is about 432.6909613696.

The spelling of 81009037 in words is "eighty-one million, nine thousand, thirty-seven".