20665145 has 8 divisors (see below), whose sum is σ = 25168704. Its totient is φ = 16285104.

The previous prime is 20665133. The next prime is 20665147. The reversal of 20665145 is 54156602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20665145 - 2¹² = 20661049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20665147) 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, 30509 + ... + 31178.

It is an arithmetic number, because the mean of its divisors is an integer number (3146088).

Almost surely, 2^20665145 is an apocalyptic number.

It is an amenable number.

20665145 is a deficient number, since it is larger than the sum of its proper divisors (4503559).

20665145 is an equidigital number, since it uses as much as digits as its factorization.

20665145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61759.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 20665145 is about 4545.8932015612. The cubic root of 20665145 is about 274.4181416450.

The spelling of 20665145 in words is "twenty million, six hundred sixty-five thousand, one hundred forty-five".