20722643 has 8 divisors (see below), whose sum is σ = 21984768. Its totient is φ = 19465344.

The previous prime is 20722621. The next prime is 20722649. The reversal of 20722643 is 34622702.

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 20722643 - 2¹² = 20718547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20722649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11630 + ... + 13292.

It is an arithmetic number, because the mean of its divisors is an integer number (2748096).

Almost surely, 2^20722643 is an apocalyptic number.

20722643 is a deficient number, since it is larger than the sum of its proper divisors (1262125).

20722643 is a wasteful number, since it uses less digits than its factorization.

20722643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2413.

The product of its (nonzero) digits is 4032, while the sum is 26.

The square root of 20722643 is about 4552.2129783216. The cubic root of 20722643 is about 274.6724165450.

The spelling of 20722643 in words is "twenty million, seven hundred twenty-two thousand, six hundred forty-three".