280235640 has 32 divisors (see below), whose sum is σ = 840707280. Its totient is φ = 74729472.

The previous prime is 280235623. The next prime is 280235653. The reversal of 280235640 is 46532082.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 280235598 and 280235607.

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, 1167529 + ... + 1167768.

Almost surely, 2^280235640 is an apocalyptic number.

280235640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

280235640 is an abundant number, since it is smaller than the sum of its proper divisors (560471640).

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

280235640 is a wasteful number, since it uses less digits than its factorization.

280235640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2335311 (or 2335307 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 280235640 is about 16740.2401416467. The cubic root of 280235640 is about 654.3967329759.

It can be divided in two parts, 280235 and 640, that added together give a triangular number (280875 = T₇₄₉).

The spelling of 280235640 in words is "two hundred eighty million, two hundred thirty-five thousand, six hundred forty".