20679421 has 6 divisors (see below), whose sum is σ = 24055710. Its totient is φ = 17725176.

The previous prime is 20679419. The next prime is 20679433. The reversal of 20679421 is 12497602.

It can be written as a sum of positive squares in only one way, i.e., 19263321 + 1416100 = 4389^2 + 1190^2 .

It is not a de Polignac number, because 20679421 - 2¹ = 20679419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20679401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 210966 + ... + 211063.

It is an arithmetic number, because the mean of its divisors is an integer number (4009285).

Almost surely, 2^20679421 is an apocalyptic number.

It is an amenable number.

20679421 is a deficient number, since it is larger than the sum of its proper divisors (3376289).

20679421 is an equidigital number, since it uses as much as digits as its factorization.

20679421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422043 (or 422036 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20679421 is about 4547.4631389380. The cubic root of 20679421 is about 274.4813187420.

The spelling of 20679421 in words is "twenty million, six hundred seventy-nine thousand, four hundred twenty-one".