66401055 has 48 divisors (see below), whose sum is σ = 132185664. Its totient is φ = 30205440.

The previous prime is 66401053. The next prime is 66401063. The reversal of 66401055 is 55010466.

It is a happy number.

66401055 is a `hidden beast` number, since 6 + 640 + 10 + 5 + 5 = 666.

It is not a de Polignac number, because 66401055 - 2¹ = 66401053 is a prime.

It is a super-2 number, since 2×66401055² = 8818200210226050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66401053) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 86875 + ... + 87635.

It is an arithmetic number, because the mean of its divisors is an integer number (2753868).

Almost surely, 2^66401055 is an apocalyptic number.

66401055 is a deficient number, since it is larger than the sum of its proper divisors (65784609).

66401055 is a wasteful number, since it uses less digits than its factorization.

66401055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056 (or 1053 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 66401055 is about 8148.6842496197. The cubic root of 66401055 is about 404.9409150203.

The spelling of 66401055 in words is "sixty-six million, four hundred one thousand, fifty-five".