20401871 has 4 divisors (see below), whose sum is σ = 23316432. Its totient is φ = 17487312.

The previous prime is 20401867. The next prime is 20401919. The reversal of 20401871 is 17810402.

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 20401871 - 2² = 20401867 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 (20401831) 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, 1457270 + ... + 1457283.

It is an arithmetic number, because the mean of its divisors is an integer number (5829108).

Almost surely, 2^20401871 is an apocalyptic number.

20401871 is a deficient number, since it is larger than the sum of its proper divisors (2914561).

20401871 is an equidigital number, since it uses as much as digits as its factorization.

20401871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2914560.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 20401871 is about 4516.8430346869. The cubic root of 20401871 is about 273.2477948017.

The spelling of 20401871 in words is "twenty million, four hundred one thousand, eight hundred seventy-one".