66621404 has 6 divisors (see below), whose sum is σ = 116587464. Its totient is φ = 33310700.

The previous prime is 66621403. The next prime is 66621407. The reversal of 66621404 is 40412666.

It is a super-2 number, since 2×66621404² = 8876822941862432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66621403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8327672 + ... + 8327679.

It is an arithmetic number, because the mean of its divisors is an integer number (19431244).

Almost surely, 2^66621404 is an apocalyptic number.

It is an amenable number.

66621404 is a deficient number, since it is larger than the sum of its proper divisors (49966060).

66621404 is a wasteful number, since it uses less digits than its factorization.

66621404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16655355 (or 16655353 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 66621404 is about 8162.1935777094. The cubic root of 66621404 is about 405.3883467021.

The spelling of 66621404 in words is "sixty-six million, six hundred twenty-one thousand, four hundred four".