21461431757 has 2 divisors, whose sum is σ = 21461431758. Its totient is φ = 21461431756.

The previous prime is 21461431711. The next prime is 21461431807. The reversal of 21461431757 is 75713416412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17133239236 + 4328192521 = 130894^2 + 65789^2 .

It is a cyclic number.

It is not a de Polignac number, because 21461431757 - 2²⁴ = 21444654541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21461439757) 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 as a sum of consecutive naturals, namely, 10730715878 + 10730715879.

It is an arithmetic number, because the mean of its divisors is an integer number (10730715879).

Almost surely, 2^21461431757 is an apocalyptic number.

It is an amenable number.

21461431757 is a deficient number, since it is larger than the sum of its proper divisors (1).

21461431757 is an equidigital number, since it uses as much as digits as its factorization.

21461431757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141120, while the sum is 41.

The spelling of 21461431757 in words is "twenty-one billion, four hundred sixty-one million, four hundred thirty-one thousand, seven hundred fifty-seven".