81025073 has 4 divisors (see below), whose sum is σ = 81151728. Its totient is φ = 80898420.

The previous prime is 81025037. The next prime is 81025093. The reversal of 81025073 is 37052018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 37052018 = 2 ⋅18526009.

It is a cyclic number.

It is not a de Polignac number, because 81025073 - 2¹² = 81020977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81025033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62363 + ... + 63648.

It is an arithmetic number, because the mean of its divisors is an integer number (20287932).

Almost surely, 2^81025073 is an apocalyptic number.

It is an amenable number.

81025073 is a deficient number, since it is larger than the sum of its proper divisors (126655).

81025073 is a wasteful number, since it uses less digits than its factorization.

81025073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126654.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 81025073 is about 9001.3928366670. The cubic root of 81025073 is about 432.7195103428.

The spelling of 81025073 in words is "eighty-one million, twenty-five thousand, seventy-three".