20662421 has 8 divisors (see below), whose sum is σ = 22672440. Its totient is φ = 18712512.

The previous prime is 20662393. The next prime is 20662423. The reversal of 20662421 is 12426602.

It can be written as a sum of positive squares in 4 ways, for example, as 4972900 + 15689521 = 2230^2 + 3961^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20662421 - 2⁶ = 20662357 is a prime.

It is a super-3 number, since 3×20662421³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20662423) 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, 14306 + ... + 15683.

It is an arithmetic number, because the mean of its divisors is an integer number (2834055).

Almost surely, 2^20662421 is an apocalyptic number.

It is an amenable number.

20662421 is a deficient number, since it is larger than the sum of its proper divisors (2010019).

20662421 is a wasteful number, since it uses less digits than its factorization.

20662421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30055.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 20662421 is about 4545.5935806009. The cubic root of 20662421 is about 274.4060835335.

The spelling of 20662421 in words is "twenty million, six hundred sixty-two thousand, four hundred twenty-one".