20670155 has 24 divisors (see below), whose sum is σ = 27782352. Its totient is φ = 14640000.

The previous prime is 20670151. The next prime is 20670163. The reversal of 20670155 is 55107602.

It is not a de Polignac number, because 20670155 - 2² = 20670151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20670151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 204605 + ... + 204705.

It is an arithmetic number, because the mean of its divisors is an integer number (1157598).

Almost surely, 2^20670155 is an apocalyptic number.

20670155 is a deficient number, since it is larger than the sum of its proper divisors (7112197).

20670155 is a wasteful number, since it uses less digits than its factorization.

20670155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 20670155 is about 4546.4442149882. Note that the first 3 decimals coincide. The cubic root of 20670155 is about 274.4403162422.

Adding to 20670155 its reverse (55107602), we get a palindrome (75777757).

The spelling of 20670155 in words is "twenty million, six hundred seventy thousand, one hundred fifty-five".