81744025 has 12 divisors (see below), whose sum is σ = 110577744. Its totient is φ = 59450000.

The previous prime is 81743999. The next prime is 81744029. The reversal of 81744025 is 52044718.

It is not a de Polignac number, because 81744025 - 2⁷ = 81743897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81744029) 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, 148351 + ... + 148900.

It is an arithmetic number, because the mean of its divisors is an integer number (9214812).

Almost surely, 2^81744025 is an apocalyptic number.

It is an amenable number.

81744025 is a deficient number, since it is larger than the sum of its proper divisors (28833719).

81744025 is a wasteful number, since it uses less digits than its factorization.

81744025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297272 (or 297267 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 81744025 is about 9041.2402357199. The cubic root of 81744025 is about 433.9956128730.

The spelling of 81744025 in words is "eighty-one million, seven hundred forty-four thousand, twenty-five".