287790640 has 20 divisors (see below), whose sum is σ = 669113424. Its totient is φ = 115116224.

The previous prime is 287790617. The next prime is 287790641. The reversal of 287790640 is 46097782.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (287790641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1798612 + ... + 1798771.

Almost surely, 2^287790640 is an apocalyptic number.

287790640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

287790640 is an abundant number, since it is smaller than the sum of its proper divisors (381322784).

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

287790640 is a wasteful number, since it uses less digits than its factorization.

287790640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3597396 (or 3597390 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 287790640 is about 16964.3932989070. The cubic root of 287790640 is about 660.2253898098.

The spelling of 287790640 in words is "two hundred eighty-seven million, seven hundred ninety thousand, six hundred forty".