66621626 has 4 divisors (see below), whose sum is σ = 99932442. Its totient is φ = 33310812.

The previous prime is 66621617. The next prime is 66621641. The reversal of 66621626 is 62612666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 49688401 + 16933225 = 7049^2 + 4115^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16655405 + ... + 16655408.

Almost surely, 2^66621626 is an apocalyptic number.

66621626 is a deficient number, since it is larger than the sum of its proper divisors (33310816).

66621626 is a wasteful number, since it uses less digits than its factorization.

66621626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33310815.

The product of its digits is 31104, while the sum is 35.

The square root of 66621626 is about 8162.2071769834. The cubic root of 66621626 is about 405.3887969884.

The spelling of 66621626 in words is "sixty-six million, six hundred twenty-one thousand, six hundred twenty-six".