81787245 has 8 divisors (see below), whose sum is σ = 130859616. Its totient is φ = 43619856.

The previous prime is 81787217. The next prime is 81787273. The reversal of 81787245 is 54278718.

It is an interprime number because it is at equal distance from previous prime (81787217) and next prime (81787273).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81787245 - 2⁷ = 81787117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81787197 and 81787206.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2726227 + ... + 2726256.

It is an arithmetic number, because the mean of its divisors is an integer number (16357452).

Almost surely, 2^81787245 is an apocalyptic number.

It is an amenable number.

81787245 is a deficient number, since it is larger than the sum of its proper divisors (49072371).

81787245 is a wasteful number, since it uses less digits than its factorization.

81787245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5452491.

The product of its digits is 125440, while the sum is 42.

The square root of 81787245 is about 9043.6300786797. The cubic root of 81787245 is about 434.0720873128.

The spelling of 81787245 in words is "eighty-one million, seven hundred eighty-seven thousand, two hundred forty-five".