66921093 has 16 divisors (see below), whose sum is σ = 99780160. Its totient is φ = 44327088.

The previous prime is 66921089. The next prime is 66921103. The reversal of 66921093 is 39012966.

It is not a de Polignac number, because 66921093 - 2² = 66921089 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66921073) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3655 + ... + 12132.

It is an arithmetic number, because the mean of its divisors is an integer number (6236260).

Almost surely, 2^66921093 is an apocalyptic number.

It is an amenable number.

66921093 is a deficient number, since it is larger than the sum of its proper divisors (32859067).

66921093 is a wasteful number, since it uses less digits than its factorization.

66921093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15953 (or 15947 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 66921093 is about 8180.5313397114. The cubic root of 66921093 is about 405.9953023472.

The spelling of 66921093 in words is "sixty-six million, nine hundred twenty-one thousand, ninety-three".