20401023021 has 4 divisors (see below), whose sum is σ = 27201364032. Its totient is φ = 13600682012.

The previous prime is 20401023017. The next prime is 20401023047. The reversal of 20401023021 is 12032010402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20401023021 - 2² = 20401023017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401023001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3400170501 + ... + 3400170506.

It is an arithmetic number, because the mean of its divisors is an integer number (6800341008).

Almost surely, 2^20401023021 is an apocalyptic number.

It is an amenable number.

20401023021 is a deficient number, since it is larger than the sum of its proper divisors (6800341011).

20401023021 is an equidigital number, since it uses as much as digits as its factorization.

20401023021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6800341010.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 20401023021 its reverse (12032010402), we get a palindrome (32433033423).

The spelling of 20401023021 in words is "twenty billion, four hundred one million, twenty-three thousand, twenty-one".