208640172280 has 32 divisors (see below), whose sum is σ = 474088321440. Its totient is φ = 82629769600.

The previous prime is 208640172259. The next prime is 208640172347. The reversal of 208640172280 is 82271046802.

It is a Harshad number since it is a multiple of its sum of digits (40).

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, 25817764 + ... + 25825843.

It is an arithmetic number, because the mean of its divisors is an integer number (14815260045).

Almost surely, 2^208640172280 is an apocalyptic number.

208640172280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

208640172280 is an abundant number, since it is smaller than the sum of its proper divisors (265448149160).

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

208640172280 is a wasteful number, since it uses less digits than its factorization.

208640172280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51643719 (or 51643715 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 40.

The spelling of 208640172280 in words is "two hundred eight billion, six hundred forty million, one hundred seventy-two thousand, two hundred eighty".