20401041021 has 4 divisors (see below), whose sum is σ = 27201388032. Its totient is φ = 13600694012.

The previous prime is 20401040987. The next prime is 20401041049. The reversal of 20401041021 is 12014010402.

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 a de Polignac number, because none of the positive numbers 2^k-20401041021 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401041121) 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, 3400173501 + ... + 3400173506.

It is an arithmetic number, because the mean of its divisors is an integer number (6800347008).

Almost surely, 2^20401041021 is an apocalyptic number.

It is an amenable number.

20401041021 is a deficient number, since it is larger than the sum of its proper divisors (6800347011).

20401041021 is an equidigital number, since it uses as much as digits as its factorization.

20401041021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6800347010.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20401041021 its reverse (12014010402), we get a palindrome (32415051423).

The spelling of 20401041021 in words is "twenty billion, four hundred one million, forty-one thousand, twenty-one".