66838725 has 18 divisors (see below), whose sum is σ = 119715986. Its totient is φ = 35647200.

The previous prime is 66838721. The next prime is 66838741. The reversal of 66838725 is 52783866.

It can be written as a sum of positive squares in 3 ways, for example, as 23357889 + 43480836 = 4833^2 + 6594^2 .

It is not a de Polignac number, because 66838725 - 2² = 66838721 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66838721) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 148306 + ... + 148755.

Almost surely, 2^66838725 is an apocalyptic number.

It is an amenable number.

66838725 is a deficient number, since it is larger than the sum of its proper divisors (52877261).

66838725 is a wasteful number, since it uses less digits than its factorization.

66838725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297077 (or 297069 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 66838725 is about 8175.4953978337. The cubic root of 66838725 is about 405.8286645507.

It can be divided in two parts, 668 and 38725, that added together give a palindrome (39393).

The spelling of 66838725 in words is "sixty-six million, eight hundred thirty-eight thousand, seven hundred twenty-five".