20401279 has 4 divisors (see below), whose sum is σ = 20486880. Its totient is φ = 20315680.

The previous prime is 20401273. The next prime is 20401291. The reversal of 20401279 is 97210402.

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 20401279 - 2¹¹ = 20399231 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 (20401273) 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, 42442 + ... + 42919.

It is an arithmetic number, because the mean of its divisors is an integer number (5121720).

Almost surely, 2^20401279 is an apocalyptic number.

20401279 is a deficient number, since it is larger than the sum of its proper divisors (85601).

20401279 is an equidigital number, since it uses as much as digits as its factorization.

20401279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85600.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 20401279 is about 4516.7775017151. Note that the first 3 decimals coincide. The cubic root of 20401279 is about 273.2451518373.

The spelling of 20401279 in words is "twenty million, four hundred one thousand, two hundred seventy-nine".