66555415 has 16 divisors (see below), whose sum is σ = 82435680. Its totient is φ = 51546240.

The previous prime is 66555409. The next prime is 66555427. The reversal of 66555415 is 51455566.

It is not a de Polignac number, because 66555415 - 2¹⁷ = 66424343 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41580 + ... + 43150.

It is an arithmetic number, because the mean of its divisors is an integer number (5152230).

Almost surely, 2^66555415 is an apocalyptic number.

66555415 is a deficient number, since it is larger than the sum of its proper divisors (15880265).

66555415 is a wasteful number, since it uses less digits than its factorization.

66555415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1842.

The product of its digits is 90000, while the sum is 37.

The square root of 66555415 is about 8158.1502192593. The cubic root of 66555415 is about 405.2544557538.

The spelling of 66555415 in words is "sixty-six million, five hundred fifty-five thousand, four hundred fifteen".