66156642 has 16 divisors (see below), whose sum is σ = 147014880. Its totient is φ = 22052196.

The previous prime is 66156617. The next prime is 66156659. The reversal of 66156642 is 24665166.

It is a happy number.

66156642 is a `hidden beast` number, since 6 + 6 + 1 + 5 + 6 + 642 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 66156597 and 66156606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 612508 + ... + 612615.

It is an arithmetic number, because the mean of its divisors is an integer number (9188430).

Almost surely, 2^66156642 is an apocalyptic number.

66156642 is an abundant number, since it is smaller than the sum of its proper divisors (80858238).

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

66156642 is a wasteful number, since it uses less digits than its factorization.

66156642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1225134 (or 1225128 counting only the distinct ones).

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

The square root of 66156642 is about 8133.6733398877. The cubic root of 66156642 is about 404.4434605353.

The spelling of 66156642 in words is "sixty-six million, one hundred fifty-six thousand, six hundred forty-two".