280695640 has 32 divisors (see below), whose sum is σ = 653346000. Its totient is φ = 108406144.

The previous prime is 280695637. The next prime is 280695643. The reversal of 280695640 is 46596082.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (280695637) and next prime (280695643).

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

It is a junction number, because it is equal to n+sod(n) for n = 280695593 and 280695602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280695643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119830 + ... + 122149.

Almost surely, 2^280695640 is an apocalyptic number.

280695640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

280695640 is an abundant number, since it is smaller than the sum of its proper divisors (372650360).

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

280695640 is a wasteful number, since it uses less digits than its factorization.

280695640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242019 (or 242015 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 280695640 is about 16753.9738569690. The cubic root of 280695640 is about 654.7545960230.

The spelling of 280695640 in words is "two hundred eighty million, six hundred ninety-five thousand, six hundred forty".