66870765 has 60 divisors (see below), whose sum is σ = 129935124. Its totient is φ = 32887296.

The previous prime is 66870761. The next prime is 66870799. The reversal of 66870765 is 56707866.

It can be written as a sum of positive squares in 6 ways, for example, as 2566404 + 64304361 = 1602^2 + 8019^2 .

It is not a de Polignac number, because 66870765 - 2² = 66870761 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66870765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66870761) 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 59 ways as a sum of consecutive naturals, for example, 67957 + ... + 68933.

Almost surely, 2^66870765 is an apocalyptic number.

66870765 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66870765 is a deficient number, since it is larger than the sum of its proper divisors (63064359).

66870765 is a wasteful number, since it uses less digits than its factorization.

66870765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020 (or 998 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The square root of 66870765 is about 8177.4546773431. The cubic root of 66870765 is about 405.8935005834.

The spelling of 66870765 in words is "sixty-six million, eight hundred seventy thousand, seven hundred sixty-five".