66990394 has 8 divisors (see below), whose sum is σ = 100886688. Its totient is φ = 33361500.

The previous prime is 66990373. The next prime is 66990401. The reversal of 66990394 is 49309966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×66990394³ (a number of 24 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66222 + ... + 67225.

It is an arithmetic number, because the mean of its divisors is an integer number (12610836).

Almost surely, 2^66990394 is an apocalyptic number.

66990394 is a deficient number, since it is larger than the sum of its proper divisors (33896294).

66990394 is a wasteful number, since it uses less digits than its factorization.

66990394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133700.

The product of its (nonzero) digits is 314928, while the sum is 46.

The square root of 66990394 is about 8184.7659709976. The cubic root of 66990394 is about 406.1353985541.

The spelling of 66990394 in words is "sixty-six million, nine hundred ninety thousand, three hundred ninety-four".