82781280 has 72 divisors (see below), whose sum is σ = 282496032. Its totient is φ = 22074624.

The previous prime is 82781273. The next prime is 82781287. The reversal of 82781280 is 8218728.

It is an interprime number because it is at equal distance from previous prime (82781273) and next prime (82781287).

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82781287) 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, 27304 + ... + 30183.

It is an arithmetic number, because the mean of its divisors is an integer number (3923556).

Almost surely, 2^82781280 is an apocalyptic number.

82781280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

82781280 is an abundant number, since it is smaller than the sum of its proper divisors (199714752).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

82781280 is a wasteful number, since it uses less digits than its factorization.

82781280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57508 (or 57497 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 82781280 is about 9098.4218411766. The cubic root of 82781280 is about 435.8235686005.

The spelling of 82781280 in words is "eighty-two million, seven hundred eighty-one thousand, two hundred eighty".