66770621 has 4 divisors (see below), whose sum is σ = 68924544. Its totient is φ = 64616700.

The previous prime is 66770609. The next prime is 66770647. The reversal of 66770621 is 12607766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12607766 = 2 ⋅6303883.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66770621 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 (66770651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1076915 + ... + 1076976.

It is an arithmetic number, because the mean of its divisors is an integer number (17231136).

Almost surely, 2^66770621 is an apocalyptic number.

It is an amenable number.

66770621 is a deficient number, since it is larger than the sum of its proper divisors (2153923).

66770621 is a wasteful number, since it uses less digits than its factorization.

66770621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2153922.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 66770621 is about 8171.3292064388. The cubic root of 66770621 is about 405.6907806720.

The spelling of 66770621 in words is "sixty-six million, seven hundred seventy thousand, six hundred twenty-one".