21486751457 has 2 divisors, whose sum is σ = 21486751458. Its totient is φ = 21486751456.

The previous prime is 21486751441. The next prime is 21486751487. The reversal of 21486751457 is 75415768412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16393217296 + 5093534161 = 128036^2 + 71369^2 .

It is a cyclic number.

It is not a de Polignac number, because 21486751457 - 2⁴ = 21486751441 is a prime.

It is not a weakly prime, because it can be changed into another prime (21486751487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10743375728 + 10743375729.

It is an arithmetic number, because the mean of its divisors is an integer number (10743375729).

Almost surely, 2^21486751457 is an apocalyptic number.

It is an amenable number.

21486751457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21486751457 is an equidigital number, since it uses as much as digits as its factorization.

21486751457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1881600, while the sum is 50.

The spelling of 21486751457 in words is "twenty-one billion, four hundred eighty-six million, seven hundred fifty-one thousand, four hundred fifty-seven".