1287784421 has 32 divisors (see below), whose sum is σ = 1700517888. Its totient is φ = 945426240.

The previous prime is 1287784409. The next prime is 1287784429. The reversal of 1287784421 is 1244877821.

It is not a de Polignac number, because 1287784421 - 2¹⁰ = 1287783397 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287784429) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 113231 + ... + 124083.

It is an arithmetic number, because the mean of its divisors is an integer number (53141184).

Almost surely, 2^1287784421 is an apocalyptic number.

1287784421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1287784421 is a deficient number, since it is larger than the sum of its proper divisors (412733467).

1287784421 is a wasteful number, since it uses less digits than its factorization.

1287784421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10961.

The product of its digits is 200704, while the sum is 44.

The square root of 1287784421 is about 35885.7133271724. The cubic root of 1287784421 is about 1087.9636590032.

The spelling of 1287784421 in words is "one billion, two hundred eighty-seven million, seven hundred eighty-four thousand, four hundred twenty-one".