20751671 has 4 divisors (see below), whose sum is σ = 21234312. Its totient is φ = 20269032.

The previous prime is 20751631. The next prime is 20751683. The reversal of 20751671 is 17615702.

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 20751671 - 2⁶ = 20751607 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 (20751631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241256 + ... + 241341.

It is an arithmetic number, because the mean of its divisors is an integer number (5308578).

Almost surely, 2^20751671 is an apocalyptic number.

20751671 is a deficient number, since it is larger than the sum of its proper divisors (482641).

20751671 is an equidigital number, since it uses as much as digits as its factorization.

20751671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 482640.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 20751671 is about 4555.4002019581. The cubic root of 20751671 is about 274.8006091841.

The spelling of 20751671 in words is "twenty million, seven hundred fifty-one thousand, six hundred seventy-one".