66166542 has 36 divisors (see below), whose sum is σ = 155244024. Its totient is φ = 20358000.

The previous prime is 66166537. The next prime is 66166549. The reversal of 66166542 is 24566166.

It is a happy number.

It is a super-2 number, since 2×66166542² = 8756022560475528, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66166497 and 66166506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66166549) 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, 7834 + ... + 13917.

It is an arithmetic number, because the mean of its divisors is an integer number (4312334).

Almost surely, 2^66166542 is an apocalyptic number.

66166542 is an abundant number, since it is smaller than the sum of its proper divisors (89077482).

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

66166542 is a wasteful number, since it uses less digits than its factorization.

66166542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21785 (or 21769 counting only the distinct ones).

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

The square root of 66166542 is about 8134.2818982379. The cubic root of 66166542 is about 404.4636338212.

The spelling of 66166542 in words is "sixty-six million, one hundred sixty-six thousand, five hundred forty-two".