20401213052261 has 4 divisors (see below), whose sum is σ = 20401990652652. Its totient is φ = 20400435451872.

The previous prime is 20401213052237. The next prime is 20401213052273. The reversal of 20401213052261 is 16225031210402.

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 8574320101636 + 11826892950625 = 2928194^2 + 3439025^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20401213052261 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 (20401213055261) 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, 388760840 + ... + 388813313.

It is an arithmetic number, because the mean of its divisors is an integer number (5100497663163).

Almost surely, 2^{20401213052261} is an apocalyptic number.

It is an amenable number.

20401213052261 is a deficient number, since it is larger than the sum of its proper divisors (777600391).

20401213052261 is an equidigital number, since it uses as much as digits as its factorization.

20401213052261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777600390.

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 20401213052261 its reverse (16225031210402), we get a palindrome (36626244262663).

The spelling of 20401213052261 in words is "twenty trillion, four hundred one billion, two hundred thirteen million, fifty-two thousand, two hundred sixty-one".