81782015 has 8 divisors (see below), whose sum is σ = 112158240. Its totient is φ = 56079072.

The previous prime is 81781991. The next prime is 81782027. The reversal of 81782015 is 51028718.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-81782015 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1168280 + ... + 1168349.

It is an arithmetic number, because the mean of its divisors is an integer number (14019780).

Almost surely, 2^81782015 is an apocalyptic number.

81782015 is a deficient number, since it is larger than the sum of its proper divisors (30376225).

81782015 is a wasteful number, since it uses less digits than its factorization.

81782015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2336641.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 81782015 is about 9043.3409202573. The cubic root of 81782015 is about 434.0628346663.

The spelling of 81782015 in words is "eighty-one million, seven hundred eighty-two thousand, fifteen".