21250406562877 has 2 divisors, whose sum is σ = 21250406562878. Its totient is φ = 21250406562876.

The previous prime is 21250406562857. The next prime is 21250406563019. The reversal of 21250406562877 is 77826560405212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12120013667161 + 9130392895716 = 3481381^2 + 3021654^2 .

It is a cyclic number.

It is not a de Polignac number, because 21250406562877 - 2²⁷ = 21250272345149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21250406562817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625203281438 + 10625203281439.

It is an arithmetic number, because the mean of its divisors is an integer number (10625203281439).

Almost surely, 2^{21250406562877} is an apocalyptic number.

It is an amenable number.

21250406562877 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250406562877 is an equidigital number, since it uses as much as digits as its factorization.

21250406562877 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11289600, while the sum is 55.

The spelling of 21250406562877 in words is "twenty-one trillion, two hundred fifty billion, four hundred six million, five hundred sixty-two thousand, eight hundred seventy-seven".