20401024421 has 4 divisors (see below), whose sum is σ = 20402330700. Its totient is φ = 20399718144.

The previous prime is 20401024411. The next prime is 20401024459. The reversal of 20401024421 is 12442010402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6247163521 + 14153860900 = 79039^2 + 118970^2 .

It is a cyclic number.

It is not a de Polignac number, because 20401024421 - 2¹⁰ = 20401023397 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20401024393 and 20401024402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401024411) 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, 629426 + ... + 661043.

It is an arithmetic number, because the mean of its divisors is an integer number (5100582675).

Almost surely, 2^20401024421 is an apocalyptic number.

It is an amenable number.

20401024421 is a deficient number, since it is larger than the sum of its proper divisors (1306279).

20401024421 is a wasteful number, since it uses less digits than its factorization.

20401024421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306278.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 20401024421 its reverse (12442010402), we get a palindrome (32843034823).

The spelling of 20401024421 in words is "twenty billion, four hundred one million, twenty-four thousand, four hundred twenty-one".