85280640 has 64 divisors (see below), whose sum is σ = 271838160. Its totient is φ = 22740992.

The previous prime is 85280639. The next prime is 85280669. The reversal of 85280640 is 4608258.

It is a tau number, because it is divible by the number of its divisors (64).

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, 20289 + ... + 24128.

Almost surely, 2^85280640 is an apocalyptic number.

85280640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

85280640 is an abundant number, since it is smaller than the sum of its proper divisors (186557520).

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

85280640 is a wasteful number, since it uses less digits than its factorization.

85280640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44439 (or 44427 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 33.

The square root of 85280640 is about 9234.7517562737. The cubic root of 85280640 is about 440.1663283014.

Adding to 85280640 its reverse (4608258), we get a palindrome (89888898).

The spelling of 85280640 in words is "eighty-five million, two hundred eighty thousand, six hundred forty".