1287652640 has 24 divisors (see below), whose sum is σ = 3042079740. Its totient is φ = 515060992.

The previous prime is 1287652633. The next prime is 1287652657. The reversal of 1287652640 is 462567821.

It can be written as a sum of positive squares in 2 ways, for example, as 1241575696 + 46076944 = 35236^2 + 6788^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4023755 + ... + 4024074.

Almost surely, 2^1287652640 is an apocalyptic number.

1287652640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1287652640 is an abundant number, since it is smaller than the sum of its proper divisors (1754427100).

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

1287652640 is an equidigital number, since it uses as much as digits as its factorization.

1287652640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8047844 (or 8047836 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 1287652640 is about 35883.8771595267. The cubic root of 1287652640 is about 1087.9265467280.

The spelling of 1287652640 in words is "one billion, two hundred eighty-seven million, six hundred fifty-two thousand, six hundred forty".