20400450051461 has 4 divisors (see below), whose sum is σ = 20734883658924. Its totient is φ = 20066016444000.

The previous prime is 20400450051437. The next prime is 20400450051511. The reversal of 20400450051461 is 16415005400402.

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 1833399948961 + 18567050102500 = 1354031^2 + 4308950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20400450051461 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 (20400450051061) 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, 167216803640 + ... + 167216803761.

It is an arithmetic number, because the mean of its divisors is an integer number (5183720914731).

Almost surely, 2^{20400450051461} is an apocalyptic number.

It is an amenable number.

20400450051461 is a deficient number, since it is larger than the sum of its proper divisors (334433607463).

20400450051461 is an equidigital number, since it uses as much as digits as its factorization.

20400450051461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334433607462.

The product of its (nonzero) digits is 19200, while the sum is 32.

Adding to 20400450051461 its reverse (16415005400402), we get a palindrome (36815455451863).

The spelling of 20400450051461 in words is "twenty trillion, four hundred billion, four hundred fifty million, fifty-one thousand, four hundred sixty-one".