20720671 has 8 divisors (see below), whose sum is σ = 21981024. Its totient is φ = 19464960.

The previous prime is 20720653. The next prime is 20720681. The reversal of 20720671 is 17602702.

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 20720671 - 2⁷ = 20720543 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 (20720611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13251 + ... + 14731.

It is an arithmetic number, because the mean of its divisors is an integer number (2747628).

Almost surely, 2^20720671 is an apocalyptic number.

20720671 is a deficient number, since it is larger than the sum of its proper divisors (1260353).

20720671 is a wasteful number, since it uses less digits than its factorization.

20720671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2321.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 20720671 is about 4551.9963752182. The cubic root of 20720671 is about 274.6637035125.

The spelling of 20720671 in words is "twenty million, seven hundred twenty thousand, six hundred seventy-one".