21001420323423 has 8 divisors (see below), whose sum is σ = 31113215294000. Its totient is φ = 14000946882264.

The previous prime is 21001420323407. The next prime is 21001420323461. The reversal of 21001420323423 is 32432302410012.

21001420323423 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 1 + 420 + 3 + 234 + 2 + 3 = 666.

It is not a de Polignac number, because 21001420323423 - 2⁴ = 21001420323407 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 777830382349 = 21001420323423 / (2 + 1 + 0 + 0 + 1 + 4 + 2 + 0 + 3 + 2 + 3 + 4 + 2 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001420323463) 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, 388915191148 + ... + 388915191201.

It is an arithmetic number, because the mean of its divisors is an integer number (3889151911750).

Almost surely, 2^{21001420323423} is an apocalyptic number.

21001420323423 is a deficient number, since it is larger than the sum of its proper divisors (10111794970577).

21001420323423 is an equidigital number, since it uses as much as digits as its factorization.

21001420323423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777830382358 (or 777830382352 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 21001420323423 its reverse (32432302410012), we get a palindrome (53433722733435).

The spelling of 21001420323423 in words is "twenty-one trillion, one billion, four hundred twenty million, three hundred twenty-three thousand, four hundred twenty-three".