1287455820 has 96 divisors (see below), whose sum is σ = 4299015168. Its totient is φ = 281478912.

The previous prime is 1287455809. The next prime is 1287455833. The reversal of 1287455820 is 285547821.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56979 + ... + 76298.

It is an arithmetic number, because the mean of its divisors is an integer number (44781408).

Almost surely, 2^1287455820 is an apocalyptic number.

1287455820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1287455820 is an abundant number, since it is smaller than the sum of its proper divisors (3011559348).

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

1287455820 is a wasteful number, since it uses less digits than its factorization.

1287455820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133319 (or 133317 counting only the distinct ones).

The product of its (nonzero) digits is 179200, while the sum is 42.

The square root of 1287455820 is about 35881.1345974455. The cubic root of 1287455820 is about 1087.8711133999.

The spelling of 1287455820 in words is "one billion, two hundred eighty-seven million, four hundred fifty-five thousand, eight hundred twenty".