20667131 has 4 divisors (see below), whose sum is σ = 20687232. Its totient is φ = 20647032.

The previous prime is 20667107. The next prime is 20667137. The reversal of 20667131 is 13176602.

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

It is a cyclic number.

It is not a de Polignac number, because 20667131 - 2⁶ = 20667067 is a prime.

It is a super-2 number, since 2×20667131² = 854260607542322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20667131.

It is not an unprimeable number, because it can be changed into a prime (20667137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8420 + ... + 10593.

It is an arithmetic number, because the mean of its divisors is an integer number (5171808).

Almost surely, 2^20667131 is an apocalyptic number.

20667131 is a deficient number, since it is larger than the sum of its proper divisors (20101).

20667131 is a wasteful number, since it uses less digits than its factorization.

20667131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20100.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 20667131 is about 4546.1116352329. Note that the first 3 decimals coincide. The cubic root of 20667131 is about 274.4269322433.

The spelling of 20667131 in words is "twenty million, six hundred sixty-seven thousand, one hundred thirty-one".