21140400461 has 2 divisors, whose sum is σ = 21140400462. Its totient is φ = 21140400460.

The previous prime is 21140400433. The next prime is 21140400467. The reversal of 21140400461 is 16400404112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21116449225 + 23951236 = 145315^2 + 4894^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21140400461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21140400467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570200230 + 10570200231.

It is an arithmetic number, because the mean of its divisors is an integer number (10570200231).

Almost surely, 2^21140400461 is an apocalyptic number.

It is an amenable number.

21140400461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140400461 is an equidigital number, since it uses as much as digits as its factorization.

21140400461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 21140400461 its reverse (16400404112), we get a palindrome (37540804573).

The spelling of 21140400461 in words is "twenty-one billion, one hundred forty million, four hundred thousand, four hundred sixty-one".