55785378987 has 24 divisors (see below), whose sum is σ = 86785206144. Its totient is φ = 34326319104.

The previous prime is 55785378983. The next prime is 55785379009. The reversal of 55785378987 is 78987358755.

55785378987 is a `hidden beast` number, since 5 + 5 + 7 + 8 + 537 + 8 + 9 + 87 = 666.

It is not a de Polignac number, because 55785378987 - 2² = 55785378983 is a prime.

It is a super-2 number, since 2×55785378987² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55785378983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2493483 + ... + 2515755.

It is an arithmetic number, because the mean of its divisors is an integer number (3616050256).

Almost surely, 2^55785378987 is an apocalyptic number.

55785378987 is a deficient number, since it is larger than the sum of its proper divisors (30999827157).

55785378987 is a wasteful number, since it uses less digits than its factorization.

55785378987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43699 (or 43696 counting only the distinct ones).

The product of its digits is 592704000, while the sum is 72.

The spelling of 55785378987 in words is "fifty-five billion, seven hundred eighty-five million, three hundred seventy-eight thousand, nine hundred eighty-seven".