81625245 has 32 divisors (see below), whose sum is σ = 148925952. Its totient is φ = 37819392.

The previous prime is 81625217. The next prime is 81625283. The reversal of 81625245 is 54252618.

It is not a de Polignac number, because 81625245 - 2¹⁴ = 81608861 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8997 + ... + 15626.

It is an arithmetic number, because the mean of its divisors is an integer number (4653936).

Almost surely, 2^81625245 is an apocalyptic number.

81625245 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81625245 is a deficient number, since it is larger than the sum of its proper divisors (67300707).

81625245 is a wasteful number, since it uses less digits than its factorization.

81625245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24661.

The product of its digits is 19200, while the sum is 33.

The square root of 81625245 is about 9034.6690586872. The cubic root of 81625245 is about 433.7853019351.

The spelling of 81625245 in words is "eighty-one million, six hundred twenty-five thousand, two hundred forty-five".