66923990 has 16 divisors (see below), whose sum is σ = 137672352. Its totient is φ = 22945344.

The previous prime is 66923971. The next prime is 66923993. The reversal of 66923990 is 9932966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66923993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 477959 + ... + 478098.

It is an arithmetic number, because the mean of its divisors is an integer number (8604522).

Almost surely, 2^66923990 is an apocalyptic number.

66923990 is an abundant number, since it is smaller than the sum of its proper divisors (70748362).

66923990 is a wasteful number, since it uses less digits than its factorization.

66923990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956071.

The product of its (nonzero) digits is 157464, while the sum is 44.

The square root of 66923990 is about 8180.7084045332. The cubic root of 66923990 is about 406.0011607464.

The spelling of 66923990 in words is "sixty-six million, nine hundred twenty-three thousand, nine hundred ninety".