1287994320 has 60 divisors (see below), whose sum is σ = 4325516676. Its totient is φ = 343464960.

The previous prime is 1287994303. The next prime is 1287994333. The reversal of 1287994320 is 234997821.

1287994320 is a `hidden beast` number, since 128 + 7 + 99 + 432 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 221057424 + 1066936896 = 14868^2 + 32664^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 893721 + ... + 895160.

Almost surely, 2^1287994320 is an apocalyptic number.

1287994320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1287994320 is an abundant number, since it is smaller than the sum of its proper divisors (3037522356).

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

1287994320 is a wasteful number, since it uses less digits than its factorization.

1287994320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788900 (or 1788891 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1287994320 is about 35888.6377562593. The cubic root of 1287994320 is about 1088.0227657073.

The spelling of 1287994320 in words is "one billion, two hundred eighty-seven million, nine hundred ninety-four thousand, three hundred twenty".