66870385 has 16 divisors (see below), whose sum is σ = 82836432. Its totient is φ = 51788800.

The previous prime is 66870371. The next prime is 66870403. The reversal of 66870385 is 58307866.

It can be written as a sum of positive squares in 8 ways, for example, as 26915344 + 39955041 = 5188^2 + 6321^2 .

It is not a de Polignac number, because 66870385 - 2¹³ = 66862193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26895 + ... + 29275.

It is an arithmetic number, because the mean of its divisors is an integer number (5177277).

Almost surely, 2^66870385 is an apocalyptic number.

It is an amenable number.

66870385 is a deficient number, since it is larger than the sum of its proper divisors (15966047).

66870385 is a wasteful number, since it uses less digits than its factorization.

66870385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2564.

The product of its (nonzero) digits is 241920, while the sum is 43.

The square root of 66870385 is about 8177.4314426964. The cubic root of 66870385 is about 405.8927317381.

The spelling of 66870385 in words is "sixty-six million, eight hundred seventy thousand, three hundred eighty-five".