66400855 has 8 divisors (see below), whose sum is σ = 79731072. Its totient is φ = 53087328.

The previous prime is 66400849. The next prime is 66400889. The reversal of 66400855 is 55800466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66400855 - 2¹⁷ = 66269783 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66400855.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7617 + ... + 13813.

It is an arithmetic number, because the mean of its divisors is an integer number (9966384).

Almost surely, 2^66400855 is an apocalyptic number.

66400855 is a deficient number, since it is larger than the sum of its proper divisors (13330217).

66400855 is a wasteful number, since it uses less digits than its factorization.

66400855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8345.

The product of its (nonzero) digits is 28800, while the sum is 34.

The square root of 66400855 is about 8148.6719776906. The cubic root of 66400855 is about 404.9405084591.

The spelling of 66400855 in words is "sixty-six million, four hundred thousand, eight hundred fifty-five".