66551406 has 32 divisors (see below), whose sum is σ = 135070848. Its totient is φ = 21858720.

The previous prime is 66551377. The next prime is 66551423. The reversal of 66551406 is 60415566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 178236 + ... + 178608.

It is an arithmetic number, because the mean of its divisors is an integer number (4220964).

Almost surely, 2^66551406 is an apocalyptic number.

66551406 is an abundant number, since it is smaller than the sum of its proper divisors (68519442).

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

66551406 is a wasteful number, since it uses less digits than its factorization.

66551406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 66551406 is about 8157.9045103507. The cubic root of 66551406 is about 405.2463186862.

The spelling of 66551406 in words is "sixty-six million, five hundred fifty-one thousand, four hundred six".