66615426 has 16 divisors (see below), whose sum is σ = 148034400. Its totient is φ = 22205124.

The previous prime is 66615397. The next prime is 66615427. The reversal of 66615426 is 62451666.

It is a happy number.

66615426 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66615426² = 8875229962322952, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66615427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 616756 + ... + 616863.

It is an arithmetic number, because the mean of its divisors is an integer number (9252150).

Almost surely, 2^66615426 is an apocalyptic number.

66615426 is an abundant number, since it is smaller than the sum of its proper divisors (81418974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66615426 is a wasteful number, since it uses less digits than its factorization.

66615426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233630 (or 1233624 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 66615426 is about 8161.8273689168. The cubic root of 66615426 is about 405.3762210494.

The spelling of 66615426 in words is "sixty-six million, six hundred fifteen thousand, four hundred twenty-six".