20670156 has 72 divisors (see below), whose sum is σ = 58247280. Its totient is φ = 6136704.

The previous prime is 20670151. The next prime is 20670163. The reversal of 20670156 is 65107602.

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, 12811 + ... + 14333.

It is an arithmetic number, because the mean of its divisors is an integer number (808990).

Almost surely, 2^20670156 is an apocalyptic number.

20670156 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20670156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29123640).

20670156 is an abundant number, since it is smaller than the sum of its proper divisors (37577124).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20670156 is a wasteful number, since it uses less digits than its factorization.

20670156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1575 (or 1570 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 20670156 is about 4546.4443249643. Note that the first 3 decimals coincide. The cubic root of 20670156 is about 274.4403206679.

Adding to 20670156 its reverse (65107602), we get a palindrome (85777758).

The spelling of 20670156 in words is "twenty million, six hundred seventy thousand, one hundred fifty-six".