1287237664 has 12 divisors (see below), whose sum is σ = 2534249214. Its totient is φ = 643618816.

The previous prime is 1287237661. The next prime is 1287237673. The reversal of 1287237664 is 4667327821.

It can be written as a sum of positive squares in only one way, i.e., 1260818064 + 26419600 = 35508^2 + 5140^2 .

It is not an unprimeable number, because it can be changed into a prime (1287237661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20113057 + ... + 20113120.

Almost surely, 2^1287237664 is an apocalyptic number.

It is an amenable number.

1287237664 is a deficient number, since it is larger than the sum of its proper divisors (1247011550).

1287237664 is an equidigital number, since it uses as much as digits as its factorization.

1287237664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40226187 (or 40226179 counting only the distinct ones).

The product of its digits is 677376, while the sum is 46.

The square root of 1287237664 is about 35878.0944867478. The cubic root of 1287237664 is about 1087.8096642967.

The spelling of 1287237664 in words is "one billion, two hundred eighty-seven million, two hundred thirty-seven thousand, six hundred sixty-four".