20722641 has 4 divisors (see below), whose sum is σ = 27630192. Its totient is φ = 13815092.

The previous prime is 20722621. The next prime is 20722649. The reversal of 20722641 is 14622702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20722641 - 2⁶ = 20722577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20722649) 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 3 ways as a sum of consecutive naturals, for example, 3453771 + ... + 3453776.

It is an arithmetic number, because the mean of its divisors is an integer number (6907548).

Almost surely, 2^20722641 is an apocalyptic number.

It is an amenable number.

20722641 is a deficient number, since it is larger than the sum of its proper divisors (6907551).

20722641 is an equidigital number, since it uses as much as digits as its factorization.

20722641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6907550.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 20722641 is about 4552.2127586483. The cubic root of 20722641 is about 274.6724077085.

The spelling of 20722641 in words is "twenty million, seven hundred twenty-two thousand, six hundred forty-one".